Intro Concepts & Frequency Distributions
Central Tendency
Variability
Z-Scores
Sampling & CI
100
The variable that is manipulated in an experiment is the:
a) controlled variable.
b) confounding variable.
c) dependent variable.
d) independent variable.
d) independent variable.
100
An outlier is:
a) the difference between the mean and an individual's raw score.
b) another term for a deviation score.
c) the score that splits a set of data in half.
d) a score that falls far away from all others in a set of data.
d) a score that falls far away from all others in a set of data.
100
Which is NOT a measure of variability?
a) interquartile range
b) variance
c) mode
d) standard deviation
c) mode
100
Which of these formulas is used to transform raw scores into z scores for a sample?
a) X = M + (z × s)
b) X – M
c) z = (X-M)/s
d) X = M – (z × s)
c) z = (X-M)/s
100
A standard error is the:
a) standard deviation of a sampling distribution.
b) typical variance of a sampling distribution.
c) standard deviation of a normal distribution.
d) predictable error of a sampling distribution.
a) standard deviation of a sampling distribution.
200
When creating a bar graph, the _____ goes on the X-axis.
a) interval-level number
b) frequency
c) set of categories of the variable
d) ratio-level number
c) set of categories of the variable
200
One advantage of the median over the mean is that the median:
a) can be used when researchers collect ratio-level data.
b) takes the differences between scores into account.
c) can be used when researchers collect nominal-level data.
d) is not as affected by the presence of outliers in a data set.
d) is not as affected by the presence of outliers in a data set.
200
What is the range for this set of scores: 17, 7, 1, 10, 5, 15, 18, 6 ?
1-18, OR 17
200
A standardized score of 0.00 indicates that an individual's raw score:
a) falls below the mean.
b) was equal to the mean.
c) falls above the mean.
d) falls above and below the mean.
b) was equal to the mean.
200
The sampling distribution of a sample mean is normally distributed; this information is handy because:
a) it means that one can calculate an unbiased standard error.
b) the percentage of cases that fall in different parts of a normal distribution is known.
c) it means that one can depend on the central limit theorem.
d) the smallest possible sample size can be used.
b)
b) the percentage of cases that fall in different parts of a normal distribution is known.
300
When calculating fc, one needs to:
a) add up the frequencies at or above a given value of a variable.
b) add up the frequencies at or below a given value of a variable.
c) take the average of the frequencies at a given value of a variable.
d) take the average of the percentages at a given value of a variable.
b) add up the frequencies at or below a given value of a variable.
300
A health psychologist is interested in knowing whether the people in the local community exercise on a regular basis. She collects data from 100 local residents and classifies them as regular exercisers and nonregular exercisers. Which measure of central tendency would be appropriate to report?
a) mean
b) variance
c) mode
d) range
c) mode
300
Morgan is analyzing her data and notices that the value of her mean is quite a bit smaller than the value of her median. She asks for your help in interpreting these results. What would you tell her?
a) These results may indicate a negatively skewed distribution.
b) These results may indicate a positively skewed distribution.
c) These results indicate a normal distribution.
d) These results cannot tell us anything about the shape of the distribution.
a) These results may indicate a negatively skewed distribution.
300
A local amusement park requires that patrons be at least 55 inches tall to go on a particular ride. If the average height was 67 inches tall with a standard deviation of 5 inches, what percentage of people would not be allowed to go on the ride?
a) 0.82 %
b) 5.00 %
c) 21.19 %
d) 40.52 %
a) 0.82 (z-score = -2.40)
300
Given that σ = 10, N = 116, and M = 90, calculate the upper limit of the confidence interval.
a) 88.18
b) 88.04
c) 91.82
d) 91.96
c) 91.82
400
For each of these phrases indicate whether it is a discrete or continuous variable.
A. the number of pairs of bowling shoes owned by all of the bowling alleys in a small city
B. the amount of red dye included in a popular soft drink
C. the number of views a particular cat video has online
A. discrete
B. continuous
C. discrete
400
A teacher records how long five parent–teacher conferences last in minutes. The duration of each meeting is 16, 13, 24, 13, and 17. What is the mean length of time the parent–teacher conference lasted?
a) 8.00 minutes
b) 13.00 minutes
c) 16.00 minutes
d) 16.60 minutes
16.60 minutes
400
If the sum of the squares equals 45.13 and the sample size is 14, what is the (a) variance and (b) standard deviation?
400
Terry completed a personality assessment and scored at the 8th percentile in neuroticism. If neuroticism is normally distributed with a mean of 10 and a standard deviation of 3, what is Terry's actual neuroticism score?
a) 3.00
b) 5.80
c) 7.50
d) 14.20
b) 5.77 (z= -1.41) OR 5.80 (z= -1.40)
400
Given σM = 1.5440 and M = 500, calculate the 95 percent confidence interval.
496.97 to 503.03
500
For each of the following descriptions of data sets, suggest the best kind of graph to present the data.
A. the number of fairgoers who went on a Ferris wheel in a single season
B. the average of "Openness to New Experiences" scores on a personality survey
C. the number of bottles of red, blonde, black, and brunette hair dye purchased by a local salon
A. bar graph
B. histogram or frequency polygon
C. bar graph
500
Given the following data, calculate the median: 25, 26, 26, 29, 40, 32, 37, and 35.
30.5
500
Calculate the IQR for this set of numbers: 17, 7, 1, 10, 5, 15, 18, 6
Q1 = (5+6)/2 = 11/2 =5.5
Q3 = (15+17)/2 = 32/2 = 16
IQR = Q3 - Q1 = 16-5.5 = 10.5
500
What z scores are most closely associated with percentile ranks of 10, 25, 50, and 80?
–1.28, –0.67, 0.00, 0.84
500
If the mean of a distribution of scores is 25.00, with a standard deviation of 2.50, what raw scores will correspond to z scores of –1.60 and –0.80?
21 and 23