The pooled two-sample t procedure is based how many degrees of freedom? (Note: n1 and n2 are the sample sizes of each group. )

A) n1 + n2 + 2 B) n1 + n2 - 2 C) n1 + n2 - 1 D) n1 + n2 A) n1 + n2 + 2 B) n1 + n2 - 2 C) n1 + n2 - 1 D) n1 + n2

A test of significance is to be carried out on the H0: F1F1F1S1F1F1F10F1F1F1S1F1F1F10= 36 against the Ha: F1F1F1S1F1F1F10 0?

A) > 46.5 B) 45.3 E) This can't be determined with the information provided. A) > 46.5 B) 45.3 E) This can't be determined with the information provided.

Bags of a certain brand of tortilla chips claim to have a net weight of 14 ounces.Net weights actually vary slightly from bag to bag.Assume net weights are Normally distributed.A representative of a consumer advocate group wishes to see if there is any evidence that the mean net weight is less than advertised and so intends to test the hypotheses H0: F1F1F1S1F1F1F10 = 14 versus Ha: F1F1F1S1F1F1F10 < 14.To do this,he selects 16 bags of tortilla chips of this brand at random and determines the net weight of each.He finds a sample mean of 13.88 ounces with a standard deviation of s = 0.24 ounces.Determine which of the following statements is true,regarding the decision the representative would make.

A) He would not reject H0 at a significance level of 0.05. B) He would reject H0 at a significance level of 0.05 but not at 0.025. C) He would reject H0 at a significance level of 0.025 but not at 0.01. D) He would reject H0 at a significance level of 0.01. A) He would not reject H0 at a significance level of 0.05. B) He would reject H0 at a significance level of 0.05 but not at 0.025. C) He would reject H0 at a significance level of 0.025 but not at 0.01. D) He would reject H0 at a significance level of 0.01.

A study was to be undertaken to determine if a particular training program would improve physical fitness.An SRS of 31 university students was selected to be enrolled in the fitness program.One important measure of fitness is maximum oxygen uptake.Measurements of oxygen uptake in untrained individuals are known to follow a Normal distribution with a mean of F1F1F1S1F1F1F10 = 45 mL/kg/min.The researchers wished to determine if there was evidence that their sample of students differed from the general population of untrained subjects.The measurements made on the subjects coming into this study produced a mean of = 47.4 mL/kg/min with a standard deviation of s = 5.3 mL/kg/min.What is the appropriate alternative hypothesis in this situation?

A) Ha: > 45 B) Ha: F1F1F1S1F1F1F10 a: F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 45 D) Ha: F1F1F1S1F1F1F10 45 E) Ha: F1F1F1S1F1F1F10 > 45 A) Ha: > 45 B) Ha: F1F1F1S1F1F1F10 a: F1F1F1S1F1F1F10 F1F1F1S1F1F1F10 45 D) Ha: F1F1F1S1F1F1F10 45 E) Ha: F1F1F1S1F1F1F10 > 45

Exam 7: Inference for Means

Twelve runners are asked to run a 10-kilometer race on each of two consecutive weeks.In one of the races,the runners wear one brand of shoe and in the other,a different brand.The brand of shoe they wear in each race is determined at random.All runners are timed and are asked to run their best in each race.The results (in minutes)are given below. Use the sign test for matched pairs to determine if there is evidence that times using Brand 1 tend to be faster than times using Brand 2.Determine which of the following statements is TRUE.

Free

(Multiple Choice)

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Question 1

Correct Answer:

Verified

Let n₁ represent the sample size of the first group and n₂ the sample size of the second group.The t procedures can be used with heavily skewed distributions when n₁ + n₂is greater than ____.

Free

(Multiple Choice)

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Question 2

Correct Answer:

Verified

A simple random sample should be used for the t procedure when the sample size is small.

Free

(True/False)

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Question 3

Correct Answer:

Verified

True

The heights (in inches)of men in the United States are believed to be Normally distributed.The average height of a random sample of 25 American adult men is found to be = 69.72 inches with a standard deviation of s = 4.15.What is the standard error of ?

(Multiple Choice)

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Question 4

A study was done to determine if students learn better in an online basic statistics class versus a traditional face-to-face (f2f)course.A random sample of 12 students in an online course and 15 students in an f2f course was taken.The scores (out of 100)on the final exam of both groups are shown below. Should a pooled t procedure be used here?

(Multiple Choice)

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Question 5

Large sample sizes are needed to find effects of small differences when comparing two means.

(True/False)

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Question 6

When the underlying assumptions for the use of t procedures are not exactly met,the probability calculations are still valid as long as the data are very close to Normal.

(True/False)

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Question 7

Two-sample t procedures are more robust than one-sample t procedures.

(True/False)

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Question 8

The pooled two-sample t procedure is based how many degrees of freedom? (Note: n₁ and n₂are the sample sizes of each group. )

(Multiple Choice)

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Question 9

When calculating a one-sample t confidence interval,which level of confidence will give the smallest interval?

(Multiple Choice)

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Question 10

A test of significance is to be carried out on the H₀: = 36 against the H_a:  < 36,based on data from an SRS selected from a Normally distributed population variable.It was decided to use a level of significance of  = 0.02 to decide whether or not to reject the null hypothesis.The sample data produced a standard deviation of s = 15.6 based on 12 sample values.What values of would lead to the rejection of H₀?

(Multiple Choice)

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Question 11

A study was conducted to determine if taking a popularly advertised herbal supplement will result in weight loss in obese males.A random sample of clinically obese males was obtained.Each subject was weighed before taking the supplement and again after 60 days using the supplement.Subjects were told not to alter their diet in any way during the study period.The following table shows the observed results for the six subjects. What are the appropriate hypotheses to use in this case to determine if the herbal supplement is effective in achieving weight loss in obese males?

(Multiple Choice)

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Question 12

When performing a two-sample t procedure,which of the following methods will help determine the degrees of freedom?

(Multiple Choice)

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Question 13

When performing a t procedure,it is best to look at the data first and then determine if you should do a one-sided or two-sided test.

(True/False)

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Question 14

A study was done to determine if students learn better in an online basic statistics class versus a traditional face-to-face (f2f)course.A random sample of 12 students in an online course and 15 students in an f2f course was taken.The scores (out of 100)on the final exam of both groups are shown below. What is the alternative hypothesis being tested?

(Multiple Choice)

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Question 15

Bags of a certain brand of tortilla chips claim to have a net weight of 14 ounces.Net weights actually vary slightly from bag to bag.Assume net weights are Normally distributed.A representative of a consumer advocate group wishes to see if there is any evidence that the mean net weight is less than advertised and so intends to test the hypotheses H₀:  = 14 versus H_a:  < 14.To do this,he selects 16 bags of tortilla chips of this brand at random and determines the net weight of each.He finds a sample mean of 13.88 ounces with a standard deviation of s = 0.24 ounces.Determine which of the following statements is true,regarding the decision the representative would make.

(Multiple Choice)

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Question 16

The probability calculations from a t procedure are valid if there are outliers in the data as long as the sample size is large and the data are Normal.

(True/False)

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Question 17

A study was to be undertaken to determine if a particular training program would improve physical fitness.An SRS of 31 university students was selected to be enrolled in the fitness program.One important measure of fitness is maximum oxygen uptake.Measurements of oxygen uptake in untrained individuals are known to follow a Normal distribution with a mean of  = 45 mL/kg/min.The researchers wished to determine if there was evidence that their sample of students differed from the general population of untrained subjects.The measurements made on the subjects coming into this study produced a mean of = 47.4 mL/kg/min with a standard deviation of s = 5.3 mL/kg/min.What is the appropriate alternative hypothesis in this situation?

(Multiple Choice)

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Question 18

Suppose a simple random sample size of n is drawn from an appropriately normal population.What degrees of freedom should be used to perform a one sample t procedure?

(Multiple Choice)

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Question 19

The hypotheses H₀:  = 10 versus H_a:   10 are examined using a sample of size n = 18.The one-sample t statistic has the value t = -2.05.Between what two values does the P-value of this test fall?

(Multiple Choice)

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Question 20

Showing 1 - 20 of 103

Let n₁ represent the sample size of the first group and n₂ the sample size of the second group.The t procedures can be used with heavily skewed distributions when n₁ + n₂is greater than ____.

A simple random sample should be used for the t procedure when the sample size is small.

The heights (in inches)of men in the United States are believed to be Normally distributed.The average height of a random sample of 25 American adult men is found to be = 69.72 inches with a standard deviation of s = 4.15.What is the standard error of ?

Large sample sizes are needed to find effects of small differences when comparing two means.

When the underlying assumptions for the use of t procedures are not exactly met,the probability calculations are still valid as long as the data are very close to Normal.

Two-sample t procedures are more robust than one-sample t procedures.

The pooled two-sample t procedure is based how many degrees of freedom? (Note: n₁ and n₂are the sample sizes of each group. )

When calculating a one-sample t confidence interval,which level of confidence will give the smallest interval?

When performing a two-sample t procedure,which of the following methods will help determine the degrees of freedom?

When performing a t procedure,it is best to look at the data first and then determine if you should do a one-sided or two-sided test.

The probability calculations from a t procedure are valid if there are outliers in the data as long as the sample size is large and the data are Normal.

Suppose a simple random sample size of n is drawn from an appropriately normal population.What degrees of freedom should be used to perform a one sample t procedure?

The hypotheses H₀:  = 10 versus H_a:   10 are examined using a sample of size n = 18.The one-sample t statistic has the value t = -2.05.Between what two values does the P-value of this test fall?

Looking at Datadistributions

Looking at Datarelationships

Producing Data

Probability: the Study of Randomness

Sampling Distributions

Introduction to Inference

Inference for Proportions

Inference for Categorical Data

Inference for Regression

Multiple Regression

One-Way Analysis of Variance

Two-Way Analysis of Variance

Logistic Regression

Nonparametric Tests

Bootstrap Methods and Permutation Tests

Statistics for Quality: Control and Capability

Filters

Exam 7: Inference for Means

Let n1 represent the sample size of the first group and n2 the sample size of the second group.The t procedures can be used with heavily skewed distributions when n1 + n2 is greater than ____.

A simple random sample should be used for the t procedure when the sample size is small.

The heights (in inches)of men in the United States are believed to be Normally distributed.The average height of a random sample of 25 American adult men is found to be = 69.72 inches with a standard deviation of s = 4.15.What is the standard error of ?

Large sample sizes are needed to find effects of small differences when comparing two means.

When the underlying assumptions for the use of t procedures are not exactly met,the probability calculations are still valid as long as the data are very close to Normal.

Two-sample t procedures are more robust than one-sample t procedures.

The pooled two-sample t procedure is based how many degrees of freedom? (Note: n1 and n2 are the sample sizes of each group. )

When calculating a one-sample t confidence interval,which level of confidence will give the smallest interval?

When performing a two-sample t procedure,which of the following methods will help determine the degrees of freedom?

When performing a t procedure,it is best to look at the data first and then determine if you should do a one-sided or two-sided test.

The probability calculations from a t procedure are valid if there are outliers in the data as long as the sample size is large and the data are Normal.

Suppose a simple random sample size of n is drawn from an appropriately normal population.What degrees of freedom should be used to perform a one sample t procedure?

The hypotheses H0:  = 10 versus Ha:   10 are examined using a sample of size n = 18.The one-sample t statistic has the value t = -2.05.Between what two values does the P-value of this test fall?

Looking at Datadistributions

Looking at Datarelationships

Producing Data

Probability: the Study of Randomness

Sampling Distributions

Introduction to Inference

Inference for Proportions

Inference for Categorical Data

Inference for Regression

Multiple Regression

One-Way Analysis of Variance

Two-Way Analysis of Variance

Logistic Regression

Nonparametric Tests

Bootstrap Methods and Permutation Tests

Statistics for Quality: Control and Capability

Filters

Let n₁ represent the sample size of the first group and n₂ the sample size of the second group.The t procedures can be used with heavily skewed distributions when n₁ + n₂is greater than ____.

The pooled two-sample t procedure is based how many degrees of freedom? (Note: n₁ and n₂are the sample sizes of each group. )

The hypotheses H₀:  = 10 versus H_a:   10 are examined using a sample of size n = 18.The one-sample t statistic has the value t = -2.05.Between what two values does the P-value of this test fall?