Deck 15: Frequencies and Distributions

Question 1

1) Deciles divide a data set up into

A) Fifths
B) Tenths
C) Twentieths
D) Hundredths

Answer 1

B

Question 2

2) If scores on a psychological variable are normally distributed then:

A) About 34% of people lie above one standard deviation
B) About 34% of people lie above two standard deviations
C) About 16% of people lie above one standard deviation
D) About 16% of people lie above two standard deviations

Answer 2

C

Question 3

3) If scores on a psychological variable have a mean of 40 and a standard deviation of 6 then:

A) About 16% of people score no higher than 34
B) About 16% of people score above 42
C) About 16% of people score between 40 and 46
D) About 16% of people score between 34 and 40

Answer 3

A

Question 4

4) A student's grade is 65 where the mean is 55 and standard deviation is 10. The proportion of the student population who would score higher than 65 is about:

A) 34%
B) 68%
C) 16%
D) 2.5%

Question 5

5) If an IQ test has a mean of 100 and a standard deviation of 15, use z tables to find what percentage of people would score between the mean and 120:

A) 27.34%
B) 40%
C) 40.82%
D) 41%

Question 6

6) In a negatively skewed distribution:

A) There are more scores above the mean than below it
B) There are more scores below the mean than above it
C) The mean is to the right of the median
D) The median is to the right of the mode

Question 7

7) A serious departure from normality occurs when:

A) The skewness statistic is the same as its standard error
B) The skewness statistic is more than half its standard error
C) The skewness statistic is more than twice its standard error
D) The skewness statistic is less than its standard error

Question 8

8) If an anxiety scale has a mean of 50 and a standard deviation of 6 then a person with a score of 65 has a z score of:

A) 1.5
B) 2.5
C) 2
D) 15

Question 9

9) The 95% confidence limits where, for 50 people, we have a mean of 40 and a standard deviation of 8 are:

A) 32 and 48
B) 37.74 and 42.26
C) 37.43 and 42.57
D) 38.87 and 41.13

Question 10

10) If a person has a percentile score of 36.69 what would be their z score?

A) .34
B) - .34
C) 1.11
D) -1.11