Which measure of central tendency will be most affected by an outlier?

Which of the following is UNTRUE of z-scores?

Ten years ago, only 15% of the U.S. population consisted of people more than 65 years old.  A researcher plans to use a sample of n = 300 people to determine whether the population distribution has changed during the past ten years.  If a chi-square test is used to evaluate the data, what is the expected frequency for the older-than-65 category?

For the following distribution, what is the width of each class interval?X              f20-24   215-19   510-14   45-9         1

What is the critical t-value of a one-tailed test with α=.05 when n = 25

Find the standard error for a sample mean with n=20 SS= 750

In a repeated-measures ANOVA, the variability within treatments is divided into two components.  What are they?

Which of these is the ONLY valid null hypothesis listed for a repeated-measures ANOVA?

The students in a psychology class seemed to think that the midterm exam was very easy. If they are correct, what is the most likely shape for the distribution of exam scores?

Which graph is the best for showing mean?