Complete the following:
1. Basic math problems:
2. -12 + 8 =
3. 4 * (-5) =
4. -5 / -4 =
5. 3 * 7 - 6 =
6. 4^3 =
7. ((8 + 3) * 2) - 5 =
8. ((2)^2)^3 =
9. 17/13 * 13/17 = (rounded to the nearest unit)
10. If 3y + 5 = 8 then y =
11 For an agricultural experiment, 300 seeds were planted in one plot and 200 were planted in a second plot. If exactly 25 percent of the seeds in the first plot germinated and exactly 35% of the seeds in the second plot germinated, what percent of the total number of seeds germinated?
Which of the following(s) can be considered (a) variable(s):
12 The IQ. Yes-No
13 The price of a stock. Yes-No
14 The number of hours in a day. Yes-No
15 The GPA. Yes-No
16 The gravity constant g = 9.81 m.s^-2. Yes-No
17 The summation sign is usually represented by
A) The Latin uppercase phi B) The Greek lowercase omega
C) The Latin lowercase t D) The Greek uppercase sigma.
Compute the mean (M), median (Md) and mode (Mo) for this distribution: 3,3,3,6,6,8,8,9,11,12
18 M =
19 Md =
20 Mo =
Find the range (R), variance (V) and standard deviation (s) for the following set of values:
100,200,300,400,500,600,700,800,900
21 R =
22 V =
23 s = (rounded to the nearest unit)
A frequency polygon:
24 does not depend on one variable. True-False
25 describes the shape of a distribution. True-False
26 can be normal or bell shaped. True-False
27 can be cumulative. True-False
28 Scores on an elementary psychology achievement test given to advanced psychology graduate students would tend to be:
A) negatively skewed.
B) positively skewed.
C) normally distributed.
D) bimodally distributed
E) leptokurtic.
29 It is better to use the median rather than the mean for a distribution when:
A) the mean will yield a score too far from the mode.
B) the extreme scores would affect the average disproportionately.
C) the standard deviation is also needed.
D) the mean is not a whole number.
E) high reliability is needed.
30 A researcher collects gross sales figures from 100 retail clothing stores in a particular city, not only sales from the half dozen extremely successful department stores, but also those from the overwhelmingly large number of small mom and pop clothing stores. When comparing sales figures,
A) the mean and the mode of the sample will be approximately equal.
B) the mean and the median of the sample will be approximately equal.
C) the mean will be greater than the median.
D) the median will be greater than the mean.
E) measurement of the mean, median and mode will be irrelevant because the distribution of sales figures will not be normal.
Suppose that an IQ test was given to a large group of persons, the scores are assumed to be from a normally distributed population, that mean = 100 and s (standard deviation) = 15. What percentage of persons earned scores:
31 below 100 ?
32 above 115 ?
33 below 70 ?
34 above 130 ?
35 between 85 and 115 ?
36 In a normal frequency distribution, 32% of the cases:
A) fall between 1 standard deviation above and 1 standard deviation below the mean.
B) fall beyond 1 standard deviation above and 1 standard deviation below the mean.
C) fall between the mode and the median.
D) fall beyond 2 standard deviations above and 2 standard deviations below the mean.
E) determine whether the distribution is leptokurtic.
37 Standard scores (Z) are useful because they always have a mean of zero and a standard deviation of one. True-False
38 In a distribution of scores, the arithmetic mean is 51, the median is 55, and the mode is 62. What is the score, in percentile form, of a subject who does less well than two-thirds of the sample?
A) 67.
B) 33.
C) 39.
D) 43.
E) 59.
39 Z scores, T scores and percentiles are very similar measures. True-False.
40 A percentile rank does not tell us where a person stands relative to their norm group. True-False.
41 A student's score falls at the 30th percentile on a 222-item test administered to a group of 100 students. This means that:
A) he got 68 items correct.
B) he got 30 items correct.
C) his score fell within +1 standard deviation of the mean.
D) his score was higher than about 70 other students.
E) his score was higher than about 30 other students.
LSAT scores are normally distributed, with a mean of 150 and s = 10. Find the Z, T and percentile equivalent of the following score: 145.
42 Z =
43 T =
44 % = (rounded to the nearest unit)
45 A correlation coefficient between variables X and Y of -.71 indicates that:
A) variables X and Y tend to decrease with time.
B) as variable X goes up, variable Y tends to go down.
C) as variable X decreases, Y tends to decrease.
D) the two variables are essentially unrelated.
E) only 29% of X is accounted for by Y.
46 The highest relationship between two sets of scores is indicated by a coefficient of:
(A) .51.
(B) .00.
(C) -.78.
(D) .40.
(E) -.40.
47 The Pearson Product-Moment Correlation Coefficient (r) is a measure of linear relationship between two variables.
True-False
Given the following data (an individual is represented by (X,Y) where X = IQ and Y = Anxiety): (111,40),(112,35),(113,30),(114,29), (114,27), (115,20), (119,6), (120,29), (130,20), (130,4), calculate (rounded to the nearest tenth):
48 the correlation between IQ and Anxiety r =
49 the coefficient of determination cd =
50 An investigator reported a correlation coefficient of +.90 between a country birth rate and the tendency of women in that country to sleep with the windows open. This can be interpreted to mean:
A) sleeping with the windows open causes an increase in the birth rate.
B) sleeping with the windows open can be hazardous to your health.
C) having many children causes one to sleep with the windows open.
D) men become more amorous in the heat.
E) when the birthrate is high, more women sleep with the windows open.