AP Statistics Midterm Review
Name:_____________________
Date:_________
Period: ____
1. You have drawn an SRS from a population. The standard deviation of the sample is a(n)
(A) Average
(B) Parameter
(C) Variance
(D) Statistic
(E) Range
2. Given the data {1, 6, 5, 4, 2, 3, 5, 4, 6, 5, 5, 7, 4, 6, 3, 5, 8, 6, 7, 9}, what is the general shape of
the distribution?
(A) Bimodal
(B) Uniform
(C) Skewed Right
(D) Skewed Left
(E) Normal
3. If you flip three coins simultaneously, what’s the probability you’ll get three heads for the first
time in the fifth toss?
(A) .125
(B) .0733
(C) .763
(D) .1094
(E) .5
4. To the nearest whole number, what percentile is associated with z = .68?
(A) 10th
(B) 25th
(C) 40th
(D) 50th
(E) 75th
5. Suppose you flip a coin n times and the probability of getting heads 15 times is .0148. What’s n?
(A) 16
(B) 17
(C) 19
(D) 20
(E) 24
6. If two events, A and B, are mutually exclusive, what else must be true?
(A) They are independent
(B) They are independent
(C) P (A  B )  1
(D) P (A  B )  0
7. In an experiment, the purpose of replication is to:
(A) reduce bias by running the experiment many times
(B) match for common characteristics of two variables
(C) reduce variability by repeating the experiment on many subjects
(D) equalize blocks in a block design
(E) ensure treatment groups are normally distributed
8. Given a set of ordered pairs (x, y) with sx  2.5 , sy  1.9 , r =.63, what is the slope of the
regression line of y on x?
(A) 1.9
(B) 2.63
(C) .76
(D) 1.32
(E) .48
9. A set of 7500 scores on a test are distributed normally, with a mean of 23 and a standard
deviation of 4. To the nearest integer value, how many scores are there between 21 and 25?
(A) 2873
(B) 5100
(C) .3830
(D) 3177
(E) 2668
10. What is  x for the discrete probability distribution shown here?
X
P
(A) 2.65
4
.5
(B) 3.21
10
.3
(C) 7
5
.2
(D) 1
(E) CBD
11. Two independent random variables x & y have x  5.2 ,  x  .72 , y  9.3 ,  y  1.44 . Find  x  y
(A) 1.47
(B) 2.59
(C) 2.16
(D) 1.61
(E) CBD
12. Which of the following statements about the correlation coefficient are true?
I. Given a set of data (xi , yi ) , the correlation coefficient if the same as the data set we
would get if we reversed each x and y value
II. Consider a bivariate data set (xi , yi ) , and a corresponding data set (zxi , zyi ) made up pf
the z-scores of the original data. For the set (zxi , zyi ) , r = the slope of the regression line.
III. r 2 represents the proportion of the variation in the dependent variable explained by the
regression o the independent variable
(A) I only
(B) II only
(C) III only
(D) I and III
(E) I, II, III
13. Researcher conduct a clinical trial on a new headache medicine. 50 subjects are each randomly
assigned to one of two groups. On of the group unknowingly receives the experimental medication and
one receives the placebo. The researcher notes that the group receiving the placebo experiences
significant relief from headaches. Which of the following is true?
I. The new medication has been shown to be ineffective in the treatment of headaches
II. This is an example of the placebo effect
III. Since the placebo is effective in treating headaches, doctors should be prescribed it
rather than a drug that might have potentially serious side effects.
(A) I only
(B) II only
(C) III only
(D) II and III
(E) I and II
14. You roll two dice, A and B. What is the probability that both dice show the same number given
that one of the dice shows a 3 or larger?
8
1
1
1
1
(A)
(B)
(C)
(D)
(E)
9
8
9
16
4
15. What does the Central Limit Theorem say in your own words.