Psychology 309w Research Methods and Statistics Quiz 8.1 Study Guide Fall 2017

For the distribution in the accompanying graph, Figure 2.1, what is the value of ΣX?

30

A skewed distribution typically has ____ tail(s) and a normal distribution has ____ tail(s).

1;2

If the following scores were placed in a stem and leaf display, how many leaves would be associated with a stem of 6? Scores: 26, 45, 62, 11, 21, 55, 66

3

For the distribution in the following table, what is the percentile rank for X = 8.5? X c% 9 100% 8 80% 7 50% 6 25%

80%

For the scores shown in the accompanying stem and leaf display, Figure 2-3, what is the highest score in the distribution?

84

For the distribution in the following table, what is the percentile rank for X = 32? X c% 30-34 100% 25-29 90% 20-24 60% 15-19 20%

95%

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?

negatively skewed

If a frequency distribution is shown in a bar graph, what scale was used to measure the scores?

nominal and ordinal

In a distribution with positive skew, scores with the highest frequencies are ____.

on the left side of the distribution

The normal distribution is ____.

symmetrical