Deck 8: A Statistics Primer

Question 1

A normal distribution is typified by:

A) a symmetrical, bell-shaped curve
B) the mean, mode, and median values being equal
C) half of the cases will fall above the mean, half will fall below the mean
D) all of the above
E) none of the above

Answer 1

D

Question 2

The proportion of male beavers in the beaver population would be computed by:

A) dividing the total number of beavers by the number of male beavers
B) dividing the total number of beavers by the number of female beavers
C) dividing the number of female beavers by the total number of female beavers
D) dividing the number of male beavers by the total number of beavers

Answer 2

D

Question 3

A researcher will standardize data in order to:

A) facilitate comparison across different units
B) facilitate comparison across distributions
C) determine the regression toward the mean
D) determine the regression away from the mean

Answer 3

A

Question 4

Given the following numbers (6, 6, 5, 5, 3, 2) one can conclude that:

A) the mode is 5
B) the mode is 6
C) the mean is 5
D) the median is 5

Question 5

Once computed, the standard deviation reflects:

A) the standardized average score
B) the variability of a distribution
C) the standard range of a distribution
D) the amount of distribution regression

Question 6

The median represents the:

A) mid-point of the distribution
B) the average score of a distribution
C) the highest occurring frequency of a distribution
D) the ordering of cases, normally from highest to lowest

Question 7

Within a normal distribution, as the number of measurement units become finer, the distribution curve will become:

A) elongated
B) rougher
C) oblong
D) smoother

Question 8

To compute the variance, one must:

A) derive the square root of the mean
B) derive the square root of the standard deviation
C) square the mean and divide by N
D) square the standard deviation

Question 9

The range may be defined as a:

A) measure of central tendency
B) measure of dispersion
C) measure of regression
D) none of the above

Question 10

To represent the above proportion of male beavers as a percentage, one would:

A) divide the proportional total by the number of female beavers
B) multiply the proportion by 100
C) square the proportional amount
D) derive the square root of the proportion

Question 11

The measure of variance is a:

A) measure of central tendency
B) measure of dispersion
C) more elaborate version of the standard deviation
D) none of the above

Question 12

Ratios permit comparison across different:

A) categories
B) units
C) medians
D) all of the above

Question 13

Given 5 test scores (5, 8, 9, 3, 6), one can conclude that the:

A) median is 5
B) mode is 9
C) mean is 5
D) the range is 6

Question 14

Given that the Canadian infant mortality rate is 8 deaths per 1000, and the American rate is 10 deaths per 1000, which of the following represents the American/Canadian infant mortality ratio:

A) 8/10
B) 1.25
C) .80
D) 1/1 or 1

Question 15

The standard deviation reveals the amount of:

A) dispersion in a distribution
B) average of many different variables
C) measure of variation in the dependent variable
D) regression towards the mean in a distribution

Question 16

The standard deviation is computed by:

A) squaring the sum of (x - mean)2 N
B) deriving the square root of (x - mean)2 N - 1
C) deriving the square root of the average of (x - mean)2 Y
D) deriving the square root of the sum of (x - mean)2 N - 1

Question 17

Which of the following is not a measure of central tendency:

A) the mean
B) the mode
C) the z-score
D) the median

Question 18

The difference between the mean and the arithmetic mean:

A) the level of measurement
B) the number of cases handled
C) the distribution type
D) no difference

Question 19

The mean is a measure which constitutes:

A) a set of observations concerning one relationship
B) a set of observations concerning one variable
C) a set of observations concerning one population of variables
D) the average of many combined variables

Question 20

The mean is calculated by:

A) squaring the standard deviation
B) determining the mid-point of a distribution
C) determining the category with the highest frequency
D) summing the values and dividing by the number of cases

Question 21

To compute a Z-score, which of the following formulas would one use:

A) (y - mean) sd
B) (x - mean) N
C) (x - mean) sd
D) (x - mean) y

Question 22

Lambda varies from:

A) -1 to 1
B) -1 to 0
C) 0 to 1
D) 0 to .5

Question 23

The Lambda statistic measures the:

A) proportionate adduction error
B) proportionate reduction rate
C) proportionate reduction in error
D) the regression toward the mean

Question 24

Within a normal distribution, what percentage of cases will fall within 2 (+ and -) deviations from the mean:

A) 50
B) 68.28
C) 95.46
D) 99

Question 25

A distribution with little variation-a small standard deviation with respect to the magnitude of variables-is said to be peaked and is referred to as:

A) bi-modal
B) platykurtic
C) leptokurtic
D) modal

Question 26

The correlation between x and y may be expressed as:

A) r2 = 1 - variation around y variation around regression
B) r = 1 - variation around y variation around regression
C) r2 = 1 - variation around regression variation around the mean of y
D) r = 1 - variation around regression variation around y

Question 27

A linear equation is expressed by which of the following:

A) Y = a + bx
B) Y = a2 + bx
C) Y = Ax(b)
D) Y = Ax b

Question 28

A Z-score measures the distance of any value in a distribution:

A) from the mode
B) from the mean
C) from the median
D) from the regression line

Question 29

Within a normal distribution, what percentage of cases will fall within one standard deviation (+ and -) of the mean:

A) 50
B) 68
C) 95
D) 0

Question 30

The higher the Lambda figure, the:

A) more error that is involved
B) more closely 2 variables are associated
C) less error that is involved
D) less closely 2 variables are related