stats questions
kterrell
spring_2015_stat_homework.docxName____________________
Date_____________________
1. The researcher using inferential statistics always makes predictions that
are based on having measured
a. a population
b. a sample
c. the entire group being predicted
d. in inferential statistics predictions are never made
2. The goal of the researcher using inferential statistics is to
a. make better-than-chance predictions
b. predict the characteristics of the entire group, based on measures taken
on a smaller group
c. describe the difference between the highest and lowest score
d. a and b, but not c
3. An example of a variable would be
a. height
b. weight
c. the number of inches in a foot
d. a and b, but not c
4. Anything that can be measured and observed to vary is called
a. a constant
b. a variable
c. an integer
d. all of these
5. The statement that one can prove anything with statistics is only true when
a. the data have been faked
b. the reader is naive regarding statistical procedures
c. the statement is always true
d. the statement is never true
6. The first attempt to employ statistical techniques for estimating
population parameters was designed in order to
a. estimate beer-drinking tastes in Dublin, Ireland
b. calculate the odds for casino gambling in France
c. calculate the probability of certain exponential functions
d. all of these
7. The first attempt to employ probability theory in a practical setting was
developed in order to
a. predict the results of presidential elections
b. predict economic forces in the market place
c. predict how consumers will evaluate new products
d. make winning bets in the gambling casinos
8. One author suggests that the best way to compare the safety of autos versus planes is on the basis of
a. the total number of deaths per year for each mode of travel
b. the total number of individuals who drive versus fly.
c. the per-hour death rate for the two modes of travel
d. none of these, since travel rates are not comparable.
9. In comparing the safety of allowing children to visit friends whose parents
own a gun versus those parents who have a swimming pool, it was found that
a. there was no safety difference between the two
b. children were safer at the homes with swimming pools
c. children were safer at the homes with guns
d. more parents had guns than swimming pools
10. Since poll results are based on a sample size which is less than the population size, generalizing from the sample to the population demands
a. data graphing
b. inferential statistics
c. descriptive statistics only
d. leap of faith
11. The commercial that specifies that a certain brand of aspirin should be used, since no other brand prevents more heart attacks proves that
a. the brand mentioned prevents more heart attacks than does its competition
b. the brand mentioned has been proven to prevent heart attacks
c. the brand mentioned has only been shown effective when combined with exercise
d. none of the above
12. When scores are arranged in order of magnitude, the researcher has formed a
a. histogram
b. measure of centrality
c. measure of dispersion
d. distribution
13. Traditionally, the researcher indicates frequency of occurrence on the
graph's
a. ordinate
b. abscissa
c. line of ascent
d. horizontal axis
14. When single points are used to designate the frequency of each score, the
points being connected by a series of straight lines, this is called a
a. frequency polygon
b. frequency rectangle
c. scatter plot
d. histogram
15. The mean, median, and mode are all measures of
a. dispersion
b. variability
c. central tendency
d. all of these
16. When a graph is constructed using a series of rectangles indicating the
frequency of occurrence for each score, it is called a
a. frequency polygon
b. frequency rectangle
c. scatter plot
d. histogram
17. The measurement which occurs most often in a distribution is called the
a. median
b. percentile
c. mean
d. mode
18. When a distribution is skewed, the researcher who is interested in central
tendency should use the
a. mean
b. median
c. mode
d. all of these are appropriate
19. When a distribution shows a large majority of very low scores and a few
very high scores, the distribution is said to be
a. skewed to the right
b. skewed to the left
c. skewed to the middle
d. bimodal
20. The influence of a few extreme scores in one direction is most pronounced
on the value of the
a. mean
b. median
c. mode
d. percentile
21. Using the mean to indicate centrality on a distribution of income scores
usually results in
a. a false image of poverty
b. an accurate portrayal of income
c. a false image of prosperity
d. income scores never lend themselves to centrality
22. The concept of "individual differences" may best be described by
a. the mode
b. the median
c. the measures of central tendency
d. the measures of variability
23. The difference between the highest and lowest scores in any distribution is
called
a. the deviation score
b. the standard deviation
c. the range
d. none of these
24. Of the following, the measure(s) of variability is (are),
a. the range
b. the standard deviation
c. the mode
d. a and b, but not c
25. One major defect of the range is that
a. it includes the entire width of the distribution
b. it is based on only two scores
c. it is not a measure of variability
d. all of these
26. The measure of the entire width of the distribution is called the
a. range
b. percentile
c. quartile
d. b and c, but not a
27. When new scores that are close to the mean are added to any distribution,
there is a fairly high probability that the range will
a. remain unaffected
b. be reduced
c. be increased
d. new scores may never be added to a distribution
28. Specific points may be located on any distribution by using the
a. percentile
b. quartile
c. decile
d. all of these
25
29. A score which is at the 95th percentile must exceed
a. at least 5% of the scores
b. at least 95% of the scores
c. at least 45% of the scores
d. at least the lowest 47.50% of the scores
30. When a student takes a 600-item standardized test and is told he/she is at
the 70th percentile, it means that the student
a. answered 30% of the items correctly
b. answered more than 70% of the items correctly
c. answered exactly 420 items correctly
d. none of these
31. A score which falls at the 50th percentile must always be at the
a. mean
b. mode
c. median
d. none of these
32. The creation of the normal curve concept is popularly credited to
a. Blaise Pascal
b. Henry Gossett
c. Sir Bryant McKenna
d. Karl Gauss
33. The normal curve is
a. symmetrical
b. unimodal
c. asymptotic to the abscissa
d. all of these
34. A bimodal distribution may never be
a. symmetrical
b. a frequency distribution
c. normal
d. all of these
35. A normal curve always has
a. a greater frequency of scores around the center than in the tails
b. a greater frequency of scores in the tails than around the center
c. a greater frequency of scores above the mean than below the mean
d. a greater frequency of scores below the mean than above the mean
36. Under the normal curve
a. the mean lies to the right of the median
b. the mode lies to the left of the mean
c. the median lies to the left of the mode
d. none of these
37. The normal curve is
a. a frequency distribution curve
b. leptokurtic
c. platykurtic
d. skewed to the left
38. When the normal curve is plotted according to standard deviation units,
each having a value of 1.00, it is called
a. platykurtic
b. leptokurtic
c. the standard normal curve
d. the deviation curve
39. Under the normal curve, 68% of the cases must always fall
a. above the mean
b. between + 1 standard deviation units from the mean
c. between + 2 standard deviation units from the mean
d. all of these, depending on the particular shape of the curve
40. Under the normal curve, 50% of the cases must always fall
a. below the mean
b. above the mean
c. below the median
d. all of these
41. When more than 34% of the cases under the curve fall between the mean and a z score of + 1, then
a. 68% of the cases fall below the mean
b. the curve cannot be symmetrical
c. the curve cannot be normal
d. none of these
