Question 1

The t-test is very sensitive to deviations from normality in the population sampled, especially for large sample sizes.

Accepted Answer

A) True 
 B)False

Question 2

In tables of critical t-values, what value of t would correspond to the location with 99% of the distribution less and 1% of the distribution greater when there are 13 degrees of freedom?

Accepted Answer

A)  1.771 
B)  2.160 
C)  2.282 
D)  2.650 
A)  1.771 
B)  2.160 
C)  2.282 
D)  2.650

Question 3

Consider an experiment in which Shireen measures 20 Arabidopsis plants in a pasture that an agricultural company claims have an average height of exactly 23 cm. Her plants have a mean of 24.53 cm with a standard deviation of 2.33 cm, however. Based on her t-test statistic, which of the following best describes her conclusion?

Accepted Answer

A)  She fails to reject the null hypothesis of the t-test and concludes that the mean height of the plants seems to differ from 23 cm. 
B)  She fails to reject the null hypothesis of the t-test and concludes that the mean height of the plants doesn't seem to differ from 23 cm. 
C)  She rejects the null hypothesis of the t-test and concludes that the mean height of the plants seems to differ from 23 cm. 
D)  She rejects the null hypothesis of the t-test and concludes that the mean height of the plants doesn't seem to differ from 23 cm. 
A)  She fails to reject the null hypothesis of the t-test and concludes that the mean height of the plants seems to differ from 23 cm. 
B)  She fails to reject the null hypothesis of the t-test and concludes that the mean height of the plants doesn't seem to differ from 23 cm. 
C)  She rejects the null hypothesis of the t-test and concludes that the mean height of the plants seems to differ from 23 cm. 
D)  She rejects the null hypothesis of the t-test and concludes that the mean height of the plants doesn't seem to differ from 23 cm.

Question 4

For a sample of 13 values that has a mean of 5.6 with a standard deviation of 0.7, what would the 99% confidence interval be?

Accepted Answer

A)  4.8 < μ < 6.4 
B)  4.9 < μ < 6.3 
C)  5.0 < μ < 6.2 
D)  5.1 < μ < 6.1 
A)  4.8 < μ < 6.4 
B)  4.9 < μ < 6.3 
C)  5.0 < μ < 6.2 
D)  5.1 < μ < 6.1

Question 5

We must use the t-distribution instead of the Z-distribution to calculate probabilities for real- world data sets because of what reason?

Accepted Answer

A)  Sampling error causing the sample and population means to differ. 
B)  Sampling error causing the samples and populations to differ. 
C)  Uncertainty about the sample's standard deviation. 
D)  Uncertainty about the population's standard deviation. 
A)  Sampling error causing the sample and population means to differ. 
B)  Sampling error causing the samples and populations to differ. 
C)  Uncertainty about the sample's standard deviation. 
D)  Uncertainty about the population's standard deviation.

Question 6

Consider a situation in which Rosa measures the diameter of 15 trees from a population that she thinks (based on published reports) has an average diameter of 240 cm. Her sample has a mean of 253.1 cm with a standard deviation of 25.21 cm. Based on her t-test statistic, which of the following best describes her conclusion?

Accepted Answer

A)  She fails to reject the null hypothesis of the t-test and concludes that the mean diameter of the trees seems to differ from 240 cm. 
B)  She fails to reject the null hypothesis of the t-test and concludes that the mean diameter of the trees doesn't seem to differ from 240 cm. 
C)  She rejects the null hypothesis of the t-test and concludes that the mean diameter of the trees seems to differ from 240 cm. 
D)  She rejects the null hypothesis of the t-test and concludes that the mean diameter of the trees doesn't seem to differ from 240 cm. 
A)  She fails to reject the null hypothesis of the t-test and concludes that the mean diameter of the trees seems to differ from 240 cm. 
B)  She fails to reject the null hypothesis of the t-test and concludes that the mean diameter of the trees doesn't seem to differ from 240 cm. 
C)  She rejects the null hypothesis of the t-test and concludes that the mean diameter of the trees seems to differ from 240 cm. 
D)  She rejects the null hypothesis of the t-test and concludes that the mean diameter of the trees doesn't seem to differ from 240 cm.

The t-test is very sensitive to deviations from normality in the population sampled, especially for large sample sizes.

In tables of critical t-values, what value of t would correspond to the location with 99% of the distribution less and 1% of the distribution greater when there are 13 degrees of freedom?

For a sample of 13 values that has a mean of 5.6 with a standard deviation of 0.7, what would the 99% confidence interval be?

We must use the t-distribution instead of the Z-distribution to calculate probabilities for real- world data sets because of what reason?

Statistics and Samples

Displaying Data

Describing Data

Estimating With Uncertainty

Probability

Hypothesis Testing

Analyzing Proportions

Fitting Probability Models to Frequency Data

Contingency Analysis: Associations Between

The Normal Distribution

Comparing Two Means

Handling Violations of Assumptions

Designing Experiments

Comparing Means of More Than Two Groups

Correlation Between Numerical Variables

Regression

Multiple Explanatory Variables

Computer-Intensive Methods

Likelihood

Meta-Analysis: Combining Information From

Filters

Exam 11: Inference for a Normal Population

The t-test is very sensitive to deviations from normality in the population sampled, especially for large sample sizes.

In tables of critical t-values, what value of t would correspond to the location with 99% of the distribution less and 1% of the distribution greater when there are 13 degrees of freedom?

For a sample of 13 values that has a mean of 5.6 with a standard deviation of 0.7, what would the 99% confidence interval be?

We must use the t-distribution instead of the Z-distribution to calculate probabilities for real- world data sets because of what reason?

Statistics and Samples

Displaying Data

Describing Data

Estimating With Uncertainty

Probability

Hypothesis Testing

Analyzing Proportions

Fitting Probability Models to Frequency Data

Contingency Analysis: Associations Between

The Normal Distribution

Comparing Two Means

Handling Violations of Assumptions

Designing Experiments

Comparing Means of More Than Two Groups

Correlation Between Numerical Variables

Regression

Multiple Explanatory Variables

Computer-Intensive Methods

Likelihood

Meta-Analysis: Combining Information From

Filters