Chapter 1
Which of the following can be treated as an interval-ratio variable?
Social security number
Zip code
Age
Hair color
Age
To find the ratio of smokers to non-smokers, you would
divide the number of smokers by the number of non-smokers
The three most commonly used measures of central tendency are
mode, median, mean
subtracting the lowest score from the highest score
On all normal curves, the area between the mean and ± 1 standard deviation will be
About 68% of the total area
Which of the following is a discrete variable?
Height
Age
Miles per gallon
Number of children
Number of children
40 of every 200 students attend all of their classes. What percentage of the student body is this?
20%
40/200 x 100 = 20%
In a ranked list of 25 scores, the median is the score of
the 13th case
The distance between the scores and the mean are called
deviations
The z score table gives the are between a score and the mean. For a z score of -1.00, that area (in percentages) is
34.13%
Which of the following is a continuous variable?
Number of children
Time spent watching TV
Number of times you have changed residences within the last five years
Number of meals you consumed yesterday
time spent watching tv
A ______ is the number of times a phenomenon occurs divided by the total possible occurrences per some unit of time.
rate
The mean defines the central tendency in terms of the
average score
The expression Σ (Xi- X̄) 2 instructs us to
sum the squared deviations
In a distribution of 150 test scores, the mean grade was an 87 and the standard deviation was 8. If a student scored a 91, what would their equivalent Z score be?
0.5
Which of the following is NOT a nominal level variable?
Level of education (10th grade, 11th grade, 12th grade)
Zip code
Occupation
Make of auto
Level of education (10th grade, 11th grade, 12th grade)
A small town of 1,709 residents had one homicide in the past year. The homicide rate for this town
is (1/1709) x 100,000
In a positively skewed distribution, the mean is
greater in value than the median
A graph used to visualize and analyze dispersion is a
boxplot or box and whiskers plot
The area between the mean and a Z score of +1.50 is 43.32%. This score is less than ____ of the scores in the distribution.
6.68%
Prejudice, when measured on a scale ranging from 'most prejudiced' to 'least prejudiced,' is an example of which level of measurement?
Ordinal
To be converted to a percentage, the proportion must be multiplied by
100
When interval-ratio data are badly skewed, the appropriate measure of central tendency is the
median
Your score on the biology test is the same as the third quartile (Q3). You may conclude that
You scored higher than 75% of the people who took the test
The Z scores of two tests scores are + 1.2 and + 1.5. To obtain the area between these scores
find the area between each score and the mean in the Z score table and then subtract the smaller area from the larger area