Final Exam Review Part 2

The average verbal SAT score for the entire class of entering freshmen is 530. However, if you select a sample of 20 freshmen and compute their average verbal SAT score you probably will not get exactly 530. What statistical concept is used to explain the natural difference that exists between a sample mean and the corresponding population mean?

• statistical error
• inferential error
• sampling error
• parametric error

Which of the following is true for most distributions?

• Around 10% of the scores will be located within one standard deviation of the mean.
• Around 15% of the scores will be located within one standard deviation of the mean.
• Around 70% of the scores will be located within one standard deviation of the mean.
• Around 90% of the scores will be located within one standard deviation of the mean.

If the data indicate a positive correlation between number of depression symptoms and number of missed work days, we can conclude that

• Depression causes people to miss more work
• Missing work causes people to become depressed
• Some other factor, like physical health problems or caring for a loved one, is causing both depression and an increase in missed work days
• Any of the choices are possible explanations

A researcher measures personality for a sample of n = 50 people and classifies each person as either Type A, Type B, or Type C personality. Which measure of central tendency would be appropriate to summarize these measurements?

• mean
• median
• mode
• any of the three measures could be used

Organizing a set of scores into a table or a graph would be an example of using ______.

• population statistics
• sample parameters
• descriptive statistics
• inferential statistics

For an ANOVA comparing three treatment conditions, what is stated by the alternative hypothesis (H1)?

• There are no differences between any of the population means.
• At least one of the three population means is different from another mean.
• All three of the population means are different from each other.
• None of the other choices are correct.

When comparing more than two treatment means, why should you use an analysis of variance instead of using several t tests?

• Using several t tests increases the risk of a Type I error.
• Using several t tests increases the risk of a Type II error.
• The analysis of variance is more likely to detect a treatment effect.
• There is no advantage to using an analysis of variance instead of several t tests.

Which of the following describes a typical distribution of F-ratios?

• Symmetrical with a mean of zero
• Positively skewed with all values greater than or equal to zero
• Negatively skewed with all values greater than or equal to zero
• Symmetrical with a mean equal to dfbetween

In general, what factors are most likely to reject the null hypothesis for an ANOVA?

• Small mean differences and small variances
• Small mean differences and large variances
• Large mean differences and small variances
• Large mean differences and large variances

What is the purpose for post-tests?

• To determine whether or not a Type I error was committed
• To determine how much difference exists between the treatments
• To determine which treatments are significantly different
• None of these