Pulse rates of adult men are approximately normal with a mean of 70 and a standard deviation of 8. Which choice correctly describes how to find the proportion of men that have a pulse rate greater than 78?

a. Find the area to the right of z = ?1 under a standard normal curve.

b. Find the area to the left of z = 1 under a standard normal curve.

b. Find the area between z = ?1 and z = 1 under a standard normal curvesss

c. Find the area to the right of z =1 under a standard normal curve.

A test to screen for a serious but curable disease is similar to hypothesis testing, with a null hypothesis of no disease, and an alternative hypothesis of disease. If the null hypothesis is rejected treatment will be given. Otherwise, it will not. Assuming the treatment does not have serious side effects, in this scenario it is better to increase the probability of:

a. making a Type 2 error, not providing treatment when it is needed.

b. making a Type 2 error, providing treatment when it is not needed

c. making a Type 1 error, providing treatment when it is not needed.

d. making a Type 1 error, not providing treatment when it is needed

The correlation coefficient is used to determine:

a. The strength of the relationship between the x and y variables

b. None of these

c. A specific value of the y-variable given a specific value of the x-variable

d. A specific value of the x-variable given a specific value of the y-variable

Suppose that a quiz consists of 20 True-False questions. A student hasn\’t studied for the exam and will just randomly guesses at all answers (with True and False equally likely). How would you find the probability that the student will get 8 or fewer answers correct?

a. Find the probability that X=8 in a binomial distribution with n = 20 and p=0.5

b. Find the cumulative probability for 8 in a binomial distribution with n = 20 and p = 0.5

c. Find the probability that X=8 for a normal distribution with mean of 10 and standard deviation of ?5

d. Find the area between 0 and 8 in a uniform distribution that goes from 0 to 20.

In regression analysis, the variable that is used to explain the change in the outcome of an experiment, or some natural process, is called

Question 5Answer

a.all alternatives are correct

b.the x-variable

c.the predictor variable

d.the independent variable

The probability is p = 0.80 that a patient with a certain disease will be successfully treated with a new medical treatment. Suppose that the treatment is used on 40 patients. What is the “expected value” of the number of patients who are successfully treated?

a.32

b.40

c.20

d.8

A random sample of 5000 students were asked whether they prefer a 10 week quarter system or a 15 week semester system. Of the 5000 students asked, 500 students responded. The results of this survey ________

a.can be generalized to the entire student body because the margin of error was 4.5%.

b.can be generalized to the entire student body because the sampling was random.

c.should not be generalized to the entire student body because the non-response rate was 90%….

d.should not be generalized to the entire student body because the margin of error was 4.5%.

A poll is done to estimate the proportion of adult Nigerians who like their jobs. The poll is based on a random sample of 400 individuals. What is the “conservative” margin of error of this poll?

a.0.1

b..0.05

c.0.025

d.0.04

In regression, the equation that describes how the response variable Yes is related to the explanatory variable (x) is:

a.the regression model

b.used to compute the correlation coefficient

c.None of these alternatives is correct.

d.the correlation model

Which of the following examples involves paired data?

a. A study compared the average number of courses taken by a random sample of 100 freshmen at a university with the average number of courses taken by a separate random sample of 100 freshmen at a community college.

b. A group of 50 students had their blood pressures measured before and after watching a movie containing violence. The mean blood pressure before the movie was compared with the mean pressure after the movie.

c. None of the altarnative.

d.A group of 100 students were randomly assigned to receive vitamin C (50 students) or a placebo (50 students). The groups were followed for 2 weeks and the proportions with colds were compared

Which statement is not true about confidence intervals?

a. A 99% confidence interval procedure has a higher probability of producing intervals that will include the population parameter than a 95% confidence interval procedure.

b. A confidence interval between 20% and 40% means that the population proportion lies between 20% and 40%

c. A confidence interval is an interval of values computed from sample data that is likely to include the true population value.

In hypothesis testing, a Type 2 error occurs when

a. The null hypothesis is rejected when the alternative hypothesis is true.

b. The null hypothesis is rejected when the null hypothesis is true.

c.The null hypothesis is not rejected when the null hypothesis is true.

d. The null hypothesis is not rejected when the alternative hypothesis is true.

Which of the following statements best describes the relationship between a parameter and a statistic?

a. A parameter is used to estimate a statistic

b. A statistic is used to estimate a parameter

c. A parameter has a sampling distribution that can be used to determine what values the statistic is likely to have in repeated samples

d. A parameter has a sampling distribution with the statistic as its mean.

The confidence level for a confidence interval for a mean is

a. the probability of making a Type 1 error if the interval is used to test a null hypothesis about the population mean.

b. the probability the procedure provides an interval that covers the sample mean

c. the probability that individuals in the population have values that fall into the interval

d. the probability the procedure provides an interval that covers the population mean.

e. 

A result is called “statistically significant” whenever

a. The p-value is less or equal to the significance level.

b. The p-value is larger than the significance level.

c. The alternative hypothesis is true

d. The null hypothesis is true

A hypothesis test is done in which the alternative hypothesis is that more than 10% of a population is left-handed. The p-value for the test is calculated to be 0.25. Which statement is correct?

a. We can conclude that more than 25% of the population is left-handed.

b.We can conclude that exactly 25% of the population is left-handed.

c.We can conclude that more than 10% of the population is left-handed.

e. We cannot conclude that more than 10% of the population is left-handed

In a past General Social Survey, a random sample of men and women answered the question “Are you a member of any sports clubs?” Based on the sample data, 95% confidence intervals for the population proportion who would answer “yes” are .13 to .19 for women and .247 to .33 for men. Based on these results, you can reasonably conclude that

a. There is no conclusive evidence of a gender difference in the proportion belonging to sports clubs

b. At least 25% of men and women belong to sports clubs.

c. At least 16% of women belong to sports clubs

d. There is a difference between the proportions of Nigerian men and Nigerian women who belong to sports clubs

Suppose that the probability of event A is 0.2 and the probability of event B is 0.4. Also, suppose that the two events are independent. Then P(A|B) is:

a. P(A) = 0.2

b. None of the above.

In a random sample of 1000 students, p^ = 0.80 (or 80%) were in favor of longer hours at the school library. The standard error of p^ (the sample proportion) is

a. 0.013

b. 0.8

c. 0.16

d. 0.64ECO251 TMA

Pulse rates of adult men are approximately normal with a mean of 70 and a standard deviation of 8. Which choice correctly describes how to find the proportion of men that have a pulse rate greater than 78?

a. Find the area to the right of z = ?1 under a standard normal curve.

b. Find the area to the left of z = 1 under a standard normal curve.

c. Find the area between z = ?1 and z = 1 under a standard normal curve

d. Find the area to the right of z =1 under a standard normal curve.

A test to screen for a serious but curable disease is similar to hypothesis testing, with a null hypothesis of no disease, and an alternative hypothesis of disease. If the null hypothesis is rejected treatment will be given. Otherwise, it will not. Assuming the treatment does not have serious side effects, in this scenario it is better to increase the probability of:

a. making a Type 2 error, not providing treatment when it is needed.

b. making a Type 2 error, providing treatment when it is not needed

c. making a Type 1 error, providing treatment when it is not needed

d. making a Type 1 error, not providing treatment when it is needed

The correlation coefficient is used to determine:

a. The strength of the relationship between the x and y variables

b. None of these

c. A specific value of the y-variable given a specific value of the x-variable

d. A specific value of the x-variable given a specific value of the y-variable

Suppose that a quiz consists of 20 True-False questions. A student hasn\’t studied for the exam and will just randomly guesses at all answers (with True and False equally likely). How would you find the probability that the student will get 8 or fewer answers correct?

a. Find the probability that X=8 in a binomial distribution with n = 20 and p=0.5

b. Find the cumulative probability for 8 in a binomial distribution with n = 20 and p = 0.5

c. Find the probability that X=8 for a normal distribution with mean of 10 and standard deviation of ?5

d. Find the area between 0 and 8 in a uniform distribution that goes from 0 to 20.

In regression analysis, the variable that is used to explain the change in the outcome of an experiment, or some natural process, is called

a. all alternatives are correct

b. the x-variable

c. the predictor variable

d. the independent variable

The probability is p = 0.80 that a patient with a certain disease will be successfully treated with a new medical treatment. Suppose that the treatment is used on 40 patients. What is the “expected value” of the number of patients who are successfully treated?

a. 32,

b. 40

c. 20

d. 8

A random sample of 5000 students were asked whether they prefer a 10 week quarter system or a 15 week semester system. Of the 5000 students asked, 500 students responded. The results of this survey ________

a. can be generalized to the entire student body because the margin of error was 4.5%.

b. can be generalized to the entire student body because the sampling was random.

c. should not be generalized to the entire student body because the non-response rate was 90

d. should not be generalized to the entire student body because the margin of error was 4.5%.

A poll is done to estimate the proportion of adult Nigerians who like their jobs. The poll is based on a random sample of 400 individuals. What is the “conservative” margin of error of this poll?

a. 0.1

b. 0.05

c. 0.025

d. 0.04

In regression, the equation that describes how the response variable Yes is related to the explanatory variable (x) is:

a. the regression model

b. used to compute the correlation coefficien

c. None of these alternatives is correct.

d. the correlation model

Which of the following examples involves paired data?

a. A study compared the average number of courses taken by a random sample of 100 freshmen at a university with the average number of courses taken by a separate random sample of 100 freshmen at a community college.

b. A group of 50 students had their blood pressures measured before and after watching a movie containing violence. The mean blood pressure before the movie was compared with the mean pressure after the movie.

c. None of the altarnative.

d. A group of 100 students were randomly assigned to receive vitamin C (50 students) or a placebo (50 students). The groups were followed for 2 weeks and the proportions with colds were compared

Which statement is not true about confidence intervals?

a. A 99% confidence interval procedure has a higher probability of producing intervals that will include the population parameter than a 95% confidence interval procedure.

b. A confidence interval between 20% and 40% means that the population proportion lies between 20% and 40%

c. A confidence interval is an interval of values computed from sample data that is likely to include the true population value.

In hypothesis testing, a Type 2 error occurs when

a. The null hypothesis is rejected when the alternative hypothesis is true.

b. The null hypothesis is rejected when the null hypothesis is true.

c. The null hypothesis is not rejected when the null hypothesis is true.

d.The null hypothesis is not rejected when the alternative hypothesis is true.

Which of the following statements best describes the relationship between a parameter and a statistic?

a. A parameter is used to estimate a statistic

b. A statistic is used to estimate a parameter

c. A parameter has a sampling distribution that can be used to determine what values the statistic is likely to have in repeated samples

d. A parameter has a sampling distribution with the statistic as its mean.

The confidence level for a confidence interval for a mean is

a. the probability of making a Type 1 error if the interval is used to test a null hypothesis about the population mean.

b. the probability the procedure provides an interval that covers the sample mean

c. the probability that individuals in the population have values that fall into the interval

d. the probability the procedure provides an interval that covers the population mean

A result is called “statistically significant” whenever

a. The p-value is less or equal to the significance level

b. The p-value is larger than the significance level.

c. The alternative hypothesis is true

d. The null hypothesis is true

A hypothesis test is done in which the alternative hypothesis is that more than 10% of a population is left-handed. The p-value for the test is calculated to be 0.25. Which statement is correct?

a. We can conclude that more than 25% of the population is left-handed.

b. We can conclude that exactly 25% of the population is left-handed.

c. We can conclude that more than 10% of the population is left-handed.

d. We cannot conclude that more than 10% of the population is left-handed

In a past General Social Survey, a random sample of men and women answered the question “Are you a member of any sports clubs?” Based on the sample data, 95% confidence intervals for the population proportion who would answer “yes” are .13 to .19 for women and .247 to .33 for men. Based on these results, you can reasonably conclude that

a. There is no conclusive evidence of a gender difference in the proportion belonging to sports clubs

b. At least 25% of men and women belong to sports clubs.

c. At least 16% of women belong to sports clubs

d. There is a difference between the proportions of Nigerian men and Nigerian women who belong to sports clubs

Suppose that the probability of event A is 0.2 and the probability of event B is 0.4. Also, suppose that the two events are independent. Then P(A|B) is:

a. P(A) = 0.2

b. None of the above.

In a random sample of 1000 students, p^ = 0.80 (or 80%) were in favor of longer hours at the school library. The standard error of p^ (the sample proportion)

a. 0.013

b. 0.8

c. 0.16

d. 0.64ECO251 TMA

Pulse rates of adult men are approximately normal with a mean of 70 and a standard deviation of 8. Which choice correctly describes how to find the proportion of men that have a pulse rate greater than 78?

a. Find the area to the right of z = ?1 under a standard normal curve.

b. Find the area to the left of z = 1 under a standard normal curve.

c. Find the area between z = ?1 and z = 1 under a standard normal curve

d. Find the area to the right of z =1 under a standard normal curve.

A test to screen for a serious but curable disease is similar to hypothesis testing, with a null hypothesis of no disease, and an alternative hypothesis of disease. If the null hypothesis is rejected treatment will be given. Otherwise, it will not. Assuming the treatment does not have serious side effects, in this scenario it is better to increase the probability of:

a. making a Type 2 error, not providing treatment when it is needed.

b. making a Type 2 error, providing treatment when it is not needed

c. making a Type 1 error, providing treatment when it is not needed

d. making a Type 1 error, not providing treatment when it is needed

The correlation coefficient is used to determine:

a. The strength of the relationship between the x and y variables

b. None of these

c. A specific value of the y-variable given a specific value of the x-variable

d. A specific value of the x-variable given a specific value of the y-variable

Suppose that a quiz consists of 20 True-False questions. A student hasn\’t studied for the exam and will just randomly guesses at all answers (with True and False equally likely). How would you find the probability that the student will get 8 or fewer answers correct?

a. Find the probability that X=8 in a binomial distribution with n = 20 and p=0.5

b. Find the cumulative probability for 8 in a binomial distribution with n = 20 and p = 0.5

c. Find the probability that X=8 for a normal distribution with mean of 10 and standard deviation of ?5

d. Find the area between 0 and 8 in a uniform distribution that goes from 0 to 20.

In regression analysis, the variable that is used to explain the change in the outcome of an experiment, or some natural process, is called

a. all alternatives are correct

b. the x-variable

c. the predictor variable

d. the independent variable

The probability is p = 0.80 that a patient with a certain disease will be successfully treated with a new medical treatment. Suppose that the treatment is used on 40 patients. What is the “expected value” of the number of patients who are successfully treated?

a. 32,

b. 40

c. 20

d. 8

A random sample of 5000 students were asked whether they prefer a 10 week quarter system or a 15 week semester system. Of the 5000 students asked, 500 students responded. The results of this survey ________

a. can be generalized to the entire student body because the margin of error was 4.5%.

b. can be generalized to the entire student body because the sampling was random.

c. should not be generalized to the entire student body because the non-response rate was 90%

d. should not be generalized to the entire student body because the margin of error was 4.5%.

A poll is done to estimate the proportion of adult Nigerians who like their jobs. The poll is based on a random sample of 400 individuals. What is the “conservative” margin of error of this poll?

a. 0.1

b. .0.05

c. 0.025

d. 0.04

In regression, the equation that describes how the response variable Yes is related to the explanatory variable (x) is:

a. the regression model

b. used to compute the correlation coefficien

c. None of these alternatives is correct.

d. the correlation model

Which of the following examples involves paired data?

a. A study compared the average number of courses taken by a random sample of 100 freshmen at a university with the average number of courses taken by a separate random sample of 100 freshmen at a community college.

b. A group of 50 students had their blood pressures measured before and after watching a movie containing violence. The mean blood pressure before the movie was compared with the mean pressure after the movie.

c. None of the altarnative.

d. A group of 100 students were randomly assigned to receive vitamin C (50 students) or a placebo (50 students). The groups were followed for 2 weeks and the proportions with colds were compared

Which statement is not true about confidence intervals?

a. A 99% confidence interval procedure has a higher probability of producing intervals that will include the population parameter than a 95% confidence interval procedure.

b. A confidence interval between 20% and 40% means that the population proportion lies between 20% and 40%

c. A confidence interval is an interval of values computed from sample data that is likely to include the true population value.

In hypothesis testing, a Type 2 error occurs when

a. The null hypothesis is rejected when the alternative hypothesis is true.

b. The null hypothesis is rejected when the null hypothesis is true.

c. The null hypothesis is not rejected when the null hypothesis is true.

d. The null hypothesis is not rejected when the alternative hypothesis is true.

Which of the following statements best describes the relationship between a parameter and a statistic?

a. A parameter is used to estimate a statistic

b. A statistic is used to estimate a parameter

c. A parameter has a sampling distribution that can be used to determine what values the statistic is likely to have in repeated samples

d.A parameter has a sampling distribution with the statistic as its mean.

The confidence level for a confidence interval for a mean is

a. the probability of making a Type 1 error if the interval is used to test a null hypothesis about the population mean.

b. the probability the procedure provides an interval that covers the sample mean

c. the probability that individuals in the population have values that fall into the interval

d. the probability the procedure provides an interval that covers the population mean

A result is called “statistically significant” whenever

a.The p-value is less or equal to the significance level

c. The p-value is larger than the significance level.

d. The alternative hypothesis is true

e. The null hypothesis is true

A hypothesis test is done in which the alternative hypothesis is that more than 10% of a population is left-handed. The p-value for the test is calculated to be 0.25. Which statement is correct?

a. We can conclude that more than 25% of the population is left-handed.

b. We can conclude that exactly 25% of the population is left-handed.

c.We can conclude that more than 10% of the population is left-handed.

d.We cannot conclude that more than 10% of the population is left-handed

In a past General Social Survey, a random sample of men and women answered the question “Are you a member of any sports clubs?” Based on the sample data, 95% confidence intervals for the population proportion who would answer “yes” are .13 to .19 for women and .247 to .33 for men. Based on these results, you can reasonably conclude that

a. There is no conclusive evidence of a gender difference in the proportion belonging to sports clubs

b. At least 25% of men and women belong to sports clubs.

c. At least 16% of women belong to sports clubs

d. There is a difference between the proportions of Nigerian men and Nigerian women who belong to sports clubs

e. 

Suppose that the probability of event A is 0.2 and the probability of event B is 0.4. Also, suppose that the two events are independent. Then P(A|B) is:

a. P(A) = 0.2

b. None of the above.

In a random sample of 1000 students, p^ = 0.80 (or 80%) were in favor of longer hours at the school library. The standard error of p^ (the sample proportion) is

a. 0.013

b. 0.8

c. 0.16

d. 0.64