Question 1

The t distribution is a family of similar probability distributions, with each individual distribution depending on a parameter known as the​

Accepted Answer

A)  ​finite correction factor. 
B)  ​sample size. 
C)  ​degrees of freedom. 
D)  ​standard deviation. 
A)  ​finite correction factor. 
B)  ​sample size. 
C)  ​degrees of freedom. 
D)  ​standard deviation.

Question 2

The ability of an interval estimate to contain the value of the population parameter is described by the

Accepted Answer

A)  confidence level. 
B)  degrees of freedom. 
C)  precise value of the population mean μ. 
D)  point estimate. 
A)  confidence level. 
B)  degrees of freedom. 
C)  precise value of the population mean μ. 
D)  point estimate.

Question 3

The following random sample from a population whose values were normally distributed was collected. 10
12
18
16
​
The 80% confidence interval for μ is

Accepted Answer

A)  12.054 to 15.946. 
B)  10.108 to 17.892. 
C)  10.321 to 17.679. 
D)  11.009 to 16.991. 
A)  12.054 to 15.946. 
B)  10.108 to 17.892. 
C)  10.321 to 17.679. 
D)  11.009 to 16.991.

Question 4

The t distribution should be used whenever​

Accepted Answer

A)  ​the sample size is less than 30. 
B)  ​the sample standard deviation is used to estimate the population standard deviation. 
C)  ​the population is not normally distributed. 
D)  ​the population standard deviation is known. 
A)  ​the sample size is less than 30. 
B)  ​the sample standard deviation is used to estimate the population standard deviation. 
C)  ​the population is not normally distributed. 
D)  ​the population standard deviation is known.

Question 5

A population has a standard deviation of 50.A random sample of 100 items from this population is selected.The sample mean is determined to be 600.At 95% confidence, the margin of error is

Accepted Answer

A)  8.225. 
B)  8.3. 
C)  9.8. 
D)  9.92. 
A)  8.225. 
B)  8.3. 
C)  9.8. 
D)  9.92.

Question 6

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period.Assume the population standard deviation is 1.8 hours.The standard error of the mean is

Accepted Answer

A)  7.50. 
B)  .39. 
C)  2.00. 
D)  .20. 
A)  7.50. 
B)  .39. 
C)  2.00. 
D)  .20.

Question 7

A sample of 75 information systems managers had an average hourly income of $40.75 with a standard deviation of $7.00.The standard error of the mean is

Accepted Answer

A)  80.83. 
B)  7.0. 
C)  .8083. 
D)  1.611. 
A)  80.83. 
B)  7.0. 
C)  .8083. 
D)  1.611.

Question 8

A random sample of 64 SAT scores of students applying for merit scholarships showed an average of 1400 with a standard deviation of 240.The margin of error at 95% confidence is

Accepted Answer

A)  1.998. 
B)  50.07. 
C)  80. 
D)  59.94. 
A)  1.998. 
B)  50.07. 
C)  80. 
D)  59.94.

Question 9

The use of the normal probability distribution as an approximation of the sampling distribution of $\bar { p }$ is based on the condition that both np and n(1 - p) equal or exceed?

Accepted Answer

A)   .05. 
B)   5. 
C)   10. 
D)   30. 
A)   .05. 
B)   5. 
C)   10. 
D)   30.

Question 10

A random sample of 64 students at a university showed an average age of 25 years and a sample standard deviation of 2 years.The 98% confidence interval for the true average age of all students in the university is

Accepted Answer

A)  20.5 to 29.5. 
B)  24.4 to 25.6. 
C)  23.0 to 27.0. 
D)  20.0 to 30.0. 
A)  20.5 to 29.5. 
B)  24.4 to 25.6. 
C)  23.0 to 27.0. 
D)  20.0 to 30.0.

Question 11

When s is used to estimate σ, the margin of error is computed by using the

Accepted Answer

A)  normal distribution. 
B)  t distribution. 
C)  mean of the sample. 
D)  mean of the population. 
A)  normal distribution. 
B)  t distribution. 
C)  mean of the sample. 
D)  mean of the population.

Question 12

The sample size that guarantees the estimate of a population proportion satisfying the margin of error requirement is computed using a planning value of p equal to​

Accepted Answer

A)  ​.01. 
B)  ​.50. 
C)  ​.51. 
D)  ​.99. 
A)  ​.01. 
B)  ​.50. 
C)  ​.51. 
D)  ​.99.

Question 13

When the level of confidence decreases, the margin of error

Accepted Answer

A)  stays the same. 
B)  becomes smaller. 
C)  becomes larger. 
D)  becomes smaller or larger, depending on the sample mean. 
A)  stays the same. 
B)  becomes smaller. 
C)  becomes larger. 
D)  becomes smaller or larger, depending on the sample mean.

Question 14

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution

Accepted Answer

A)  becomes larger. 
B)  becomes smaller. 
C)  stays the same. 
D)  fluctuates. 
A)  becomes larger. 
B)  becomes smaller. 
C)  stays the same. 
D)  fluctuates.

Question 15

We can use the normal distribution to make confidence interval estimates for the population proportion, p, when​

Accepted Answer

A)  ​np > 5. 
B)  ​n(1 - p) > 5. 
C)  ​p has a normal distribution. 
D)  ​both np > 5 and n(1 - p) > 5. 
A)  ​np > 5. 
B)  ​n(1 - p) > 5. 
C)  ​p has a normal distribution. 
D)  ​both np > 5 and n(1 - p) > 5.

Question 16

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period.Assume the population standard deviation is 1.8 hours.With a .95 probability, the margin of error is approximately

Accepted Answer

A)  .39. 
B)  1.96. 
C)  .20. 
D)  1.64. 
A)  .39. 
B)  1.96. 
C)  .20. 
D)  1.64.

Question 17

In order to estimate the average electric usage per month, a sample of 81 houses was selected and the electric usage was determined.Assume a population standard deviation of 450 kilowatt-hours.At 95% confidence, the size of the margin of error is

Accepted Answer

A)  1.96. 
B)  50.00. 
C)  98.00. 
D)  42.00. 
A)  1.96. 
B)  50.00. 
C)  98.00. 
D)  42.00.

Question 18

Using an α = .04, a confidence interval for a population proportion is determined to be .65 to .75.For the same data, if α is decreased, the confidence interval for the population proportion

Accepted Answer

A)  becomes narrower. 
B)  becomes wider. 
C)  uses a zero margin of error. 
D)  remains the same. 
A)  becomes narrower. 
B)  becomes wider. 
C)  uses a zero margin of error. 
D)  remains the same.

The t distribution is a family of similar probability distributions, with each individual distribution depending on a parameter known as the

The ability of an interval estimate to contain the value of the population parameter is described by the

The following random sample from a population whose values were normally distributed was collected. 10 12 18 16 The 80% confidence interval for μ is

The t distribution should be used whenever

A population has a standard deviation of 50.A random sample of 100 items from this population is selected.The sample mean is determined to be 600.At 95% confidence, the margin of error is

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period.Assume the population standard deviation is 1.8 hours.The standard error of the mean is

A sample of 75 information systems managers had an average hourly income of $40.75 with a standard deviation of $7.00.The standard error of the mean is

A random sample of 64 SAT scores of students applying for merit scholarships showed an average of 1400 with a standard deviation of 240.The margin of error at 95% confidence is

The use of the normal probability distribution as an approximation of the sampling distribution of $\bar { p }$ is based on the condition that both np and n(1 - p) equal or exceed?

A random sample of 64 students at a university showed an average age of 25 years and a sample standard deviation of 2 years.The 98% confidence interval for the true average age of all students in the university is

When s is used to estimate σ, the margin of error is computed by using the

The sample size that guarantees the estimate of a population proportion satisfying the margin of error requirement is computed using a planning value of p equal to

When the level of confidence decreases, the margin of error

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution

We can use the normal distribution to make confidence interval estimates for the population proportion, p, when

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period.Assume the population standard deviation is 1.8 hours.With a .95 probability, the margin of error is approximately

In order to estimate the average electric usage per month, a sample of 81 houses was selected and the electric usage was determined.Assume a population standard deviation of 450 kilowatt-hours.At 95% confidence, the size of the margin of error is

Using an α = .04, a confidence interval for a population proportion is determined to be .65 to .75.For the same data, if α is decreased, the confidence interval for the population proportion

Data and Statistics

Descriptive Statistics: Tabulargraphical

Descriptive Statistics: Numerical

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Filters

Exam 8: Interval Estimation

The t distribution is a family of similar probability distributions, with each individual distribution depending on a parameter known as the​

The ability of an interval estimate to contain the value of the population parameter is described by the

The following random sample from a population whose values were normally distributed was collected. 10 12 18 16 ​ The 80% confidence interval for μ is

The t distribution should be used whenever​

A population has a standard deviation of 50.A random sample of 100 items from this population is selected.The sample mean is determined to be 600.At 95% confidence, the margin of error is

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period.Assume the population standard deviation is 1.8 hours.The standard error of the mean is

A sample of 75 information systems managers had an average hourly income of $40.75 with a standard deviation of $7.00.The standard error of the mean is

A random sample of 64 SAT scores of students applying for merit scholarships showed an average of 1400 with a standard deviation of 240.The margin of error at 95% confidence is

The use of the normal probability distribution as an approximation of the sampling distribution of pˉ\bar { p }pˉ​ is based on the condition that both np and n(1 - p) equal or exceed?

A random sample of 64 students at a university showed an average age of 25 years and a sample standard deviation of 2 years.The 98% confidence interval for the true average age of all students in the university is

When s is used to estimate σ, the margin of error is computed by using the

The sample size that guarantees the estimate of a population proportion satisfying the margin of error requirement is computed using a planning value of p equal to​

When the level of confidence decreases, the margin of error

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution

We can use the normal distribution to make confidence interval estimates for the population proportion, p, when​

In order to estimate the average time spent per student on the computer terminals at a local university, data were collected for a sample of 81 business students over a one-week period.Assume the population standard deviation is 1.8 hours.With a .95 probability, the margin of error is approximately

In order to estimate the average electric usage per month, a sample of 81 houses was selected and the electric usage was determined.Assume a population standard deviation of 450 kilowatt-hours.At 95% confidence, the size of the margin of error is

Using an α = .04, a confidence interval for a population proportion is determined to be .65 to .75.For the same data, if α is decreased, the confidence interval for the population proportion

Data and Statistics

Descriptive Statistics: Tabulargraphical

Descriptive Statistics: Numerical

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Filters

The t distribution is a family of similar probability distributions, with each individual distribution depending on a parameter known as the

The following random sample from a population whose values were normally distributed was collected. 10 12 18 16 The 80% confidence interval for μ is

The t distribution should be used whenever

The use of the normal probability distribution as an approximation of the sampling distribution of $\bar { p }$ is based on the condition that both np and n(1 - p) equal or exceed?

The sample size that guarantees the estimate of a population proportion satisfying the margin of error requirement is computed using a planning value of p equal to

We can use the normal distribution to make confidence interval estimates for the population proportion, p, when