Chapter 2

B. 7

A sample of n = 20 scores ranges from a high of X = 9 to a low of X = 3.If these scores are placed in a frequency distribution table, how many X values will be listed in the first column? A. 20 B.7 C.9 D.6

C. 5-9

A set of scores ranges from a high of X =48 to a low of X = 7. If these scores are placed in a grouped frequency distribution table with an interval width of 5 points, the bottom interval in the table would be _______. A. 7-11 B. 5-10 C. 5-9 D. 7-12

A. 1,2

A skewed distribution typically has _____ distinct tail(s) and a normal distribution has ____ distinct tail(s). A. 1,2 B. 2,2 C. 1,1 D. 2,1

Rules for Grouped Frequency Distributions

About 10 intervals total Width of interval should be simple bottom score in interval should be a multiple of the width intervals should be the same width

continuous

For ____ variable, the score must correspond to an internal on the number line

Relative frequency

For populations that are too large a _________ is used

D. n=9

For the following frequency distribution of quiz scores, how many individuals took the quiz? X F _______________________ 5 2 4 4 3 2 2 1 A. cannot be determined B. n=15 C. n=5 D. n=9

A. X=14.5 to X=19.5

If the following distribution was shown in a histogram, the bar above the 15-19 interval would reach from _____ to _____. A. X=14.5 TO X=19.5 B. X=15.5 TO X=18.5 C. X=15.0 TO X=19.0 D. X=15.5 TO X=19.5

A. the scores pile up in the middle and taper off symmetrically to both sides

In a normal shaped distribution, ______. A. the scores pile up in the middle and taper off symmetrically to both sides. B. the scores pile up on the right-hand side and taper off to the left. C. the scores are evenly distributed across the entire scale of measurement. D. the scores pile up on the left-hand side and taper off to the right.

C. on the left side of the distribution

In a positively skewed distribution, scores with the highest frequencies are _____. A. represented at two distinct peaks B. in the middle of the distribution C. on the left side of the distribution D. on the right side of the distribution

B. a bar graph

The classrooms in the Psychology department are numbered from 100 to 120. A professor records the number of classes held in each room during the fall semester. If these values are presented in a frequency distribution graph, what kind of graph would be appropriate? A. a histogram or a polygon B. a bar graph C. a polygon D. a histogram

to present a distribution that makes the data more understandable

What is the goal of frequency distribution?

C) positively skewed

What is the shape of the distribution for the following set of data? Scores: 1, 2, 2, 2, 2, 3, 3, 4, 5, 6 A. symmetrical B. rectangular C. positively skewed D. negatively skewed

Histogram

a bar is centered above each score so that the height of the bar corresponds to the frequency and the width extends to the real limits, so the adjacent bars touch

polygon

a dot is centered above each score so that the height of the dot corresponds to the frequency, the dots are then connected by straight lines, an additional line is drawn at zero on both ends

Proportion=p=

f/N

smaller

for grouped frequency distributions the apparent limits are __________ than the real limits

smooth curve

if information is presented on an interval scale or ratio scale it is presented with a

frequency distribution

is an organized tabulation of the number of individuals located in each category on the scale of measurement

bar graph

is just like a histogram except that gaps or spaces are left between adjacent bars -used for nominal and ordinal scales

percentile rank

the percentage of scores below a specific score in a distribution of scores

Frequency distribution graph

the score categories (X values) are listed on the X axis and the frequencies are listed on the Y axis

positively skewed

the scores tend to pile up on the left side of the distribution with the tail tapering off to the right

negatively skewed

the scores tend to pile up on the right side and the tail points to the left

Skewed

when a distribution is not symmetric and one tail stretches out farther than the other

Symmetrical Distribution

when the left side of the graph mirrors the right side