This document contains 50 multiple choice questions covering topics in introductory statistics including: types of variables, measures of central tendency, normal distributions, confidence intervals, sampling distributions, and the t-distribution. The questions range in difficulty from identifying basic statistical terminology and concepts to applying statistical reasoning and calculations to word problems.

1. STAT200
1. The newspaper reports that higher rates of sunburn and ice
cream consumption correspond. Does that mean that eating ice
cream can put you at risk of sunburn? What might be the reason
behind this phenomenon?
a. Kids are not waiting 40 minutes after eating to swim
b. In summer both ice cream consumption and rates of sunburn
increase
c. Eating ice cream is viewed as a replacement for sunblock
2. A prospective graduate student may be interested in class
size at the university s/he will attend. Data on how many
students were in last years incoming class is an example of:
a. Descriptive statistics
b. Inferential statistics
3. The following distribution has:
a. A positive skew
b. A left skew
c. No skew
4. A normal or bell shaped distribution has its greatest
probability density in the middle.

2. a. True
b. False
5. Which of the following is a qualitative variable?
a. Weight in pounds
b. Number of days of precipitation
c. Race
d. Average daily high temperature
6. Identify the scale of measurement for the following:
temperature measured in centigrade
a. Nominal
b. Ordinal
c. Interval
d. Ratio
7. For the following data:
a. 1
b. 16
c. 49
d. 7

3. 8. The lowest value in the dataset is (multiply stems by 10.0):
a. 19
b. 13.2
c. 13
d. 1.9
9. The following bar chart shows percent increase in the
consumer price index for four three-month periods ending the
date shown:
In which quarter did the CPI increase the most, in percentage
terms?
a. the quarter ending July 2000
b. the quarter ending October 2000
c. the quarter ending January 2001
d. the quarter endinig April
10. For the following histogram of test scores,
The majority of scores came between______
a. 39.5 and 49.5
b. 89.5 and 99.5
c. 79.5 and 89.5
d. 159.5 and 169.5

4. 11. For the following line graph of quarterly percentage
changes in five components of the CPI, which component
steadily increased from quarter to quarter?
a. Housing
b. Medical Care
c. Food and Beverage
d. Recreation
e. Transportation
12. The area under the curve of a probability distribution is
_____
a. 0
b. 100
c. .68

5. d. 1
13. Which of the following is a qualitative variable?
a. Weight in kilograms
b. Number of days without precipitation
c. Ethnicity
d. Average daily temperature
14. The highest value in the dataset is (multiply stems by 10.0):
a. 132
b. 13.2
c. 13
d. 1.32
15. Low-density lipoprotein (LDL) is an important part of
blood cholesterol test. LDL higher than 130mg/dl is a risk
factor of developing cardiovascular disease. To prevent
cardiovascular disease, a health center had a free blood
cholesterol test for all the people older than 65 in the
community. A total of eight people attended the blood screening
and their blood test results are listed below:
LDL(mg/dl): 130,143,114,110,123,110,134,124

6. After the blood test, the nurse wants to know the variance of
LDL scores
16. Rachael and Peter are discussing how the mean value and
variance affect the distribution graph. As the following graph
shows, there are two distributions: A and B
Peter said that the distribution A has fatter tail because its has
bigger standard deviation than the distribution B. Rachael's
answer is different:she thinks the distribution A has a smaller
standard deviation than the distribution B.
Who do you think is right?
a. Peter
b. Rachael
c. None of them are right. Distribution A and Distribution B
have the same standard Deviation
17. The singular form of the word “dice” is “die”. Tom was
throwing a six-sided die. The first time he threw, he got a three;
the second time he threw, he got a three again. What’s the
probability of getting a three at the third time?
18. Rachel was flipping a coin with Jerry. She told jerry: “I am
able to get all heads in two tosses.” Jerry laughed at her: “No,
the probability of getting two heads at two tosses is only__”

7. 19. Jennie and Alex both wanted to get a free ticket for a
College Music concert. However, the concert staff told them the
tickets were limited. Twenty people wanted to attend the
concert but only 10 free tickets were left. So the concert center
staff decided to use a lottery to decide who would receive the
free tickets. What’s the probability of Jennie and Alex both
getting free tickets?
20. Laura and Melissa were playing dice. What the probability
of Laura and Melissa both getting a 6?
21. In a statistics class with 36 students, the professor wanted to
know the probability that at least two students share the same
birthday. The probability will be___
a. 0.1
b. Much smaller than 0.1
c. Much bigger than 0.1
d. Not possible

8. 22. If you throw a die for two times, what is the probability
that you will get a one on the first throw or a one on the second
throw (or both)?
23. Jerry got a box full of colorful candy balls. There were 50
of them: 20 red, 10 green, 12 yellow and 8 blue. After shaking
the box, he randomly selected 2 candy balls from the box.
What’s the probability that the first one was blue and the second
one was yellow?
24. Which activity could probabilities be computed using a
Binomial Distribution?
a. Flipping a coin a 100 times
b. Throwing a die one hundred times
c. The probability of getting a heart while playing card games
d. Grades earned by 100 students on a statistics final exam
25. Many researchers have argued that the TB skin test is not
accurate. Imagine that the TB skin test is only 70% accurate.
Sarah is thinking about having the test. Before she has the test
she wonders the probability that she has TB. The probability of
Sarah having TB is …

9. a. 70%
b. 35%
c. 30%
d. More information needed to calculate
26. Imagine that the diabetic test accurately indicates the
disease in 95% of the people who have it. What’s the miss rate?
27. Which of the following is the probability that subjects do
not have the disease, but the test result is positive?
a. Miss rate
b. False positive rate
c. Base rate
d. Disease rate
28. In a normal distribution, the median is ____it’s mean and
mode.
a. Approximately equal to
b. Bigger than
c. Smaller than
d. Unrelated to
29. In a normal distribution, __ percentage of the area under

10. the curve is within one standard deviations of the mean?
a. 68%
b. 100%
c. 95%
d. It depends on the values of the mean and standard deviation
30. A normal distribution with a mean of 15 and standard
deviation of 5. 95% of its area is within__
a. One standard deviation of the mean
b. Two standard deviations of the mean
c. Three standard deviations of the mean
d. It depends on the value of the mode
31. The mean of a standard normal distribution is:
a. 0
b. 1.0
c. -1.0
d. 100
32. The standard deviation of the mean for a standard
distribution is:
a. 0.0
b. 1.0
c. 100

11. d. 68%
33. A normal distribution with a mean of 25 and standard
deviation of 5. What is the corresponding Z score for a case
having a value of 10?
34. Consider a normal distribution with a mean of 25 and
standard deviation of 4. Approximately, what proportion of the
area lies between values of 17 and 33.
a. 95%
b. 68%
c. 99%
d. 50%
35. Consider a normal distribution with a mean of 10 and
standard deviation of 25. What’s the Z score for the value of
35?
36. For a standard normal distribution, what’s the probability
of getting a positive number?
a. 50%
b. 95%

12. c. 68%
d. We cannot tell from the given information
37. Two-hundred students took a statistics class. Their
professor creatively decided to give each of them their Z-score
instead of their grade. Rachel got her Z-score of -0.2. She was
wondering how well she did on the exam.
a. It was very good, much better than almost all of the other
students
b. It was so-so, but still better than half of the students.
c. It was not that good, but not at the bottom of the distribution
d. It was very bad and she needs to work much harder next time
38. A researcher collected some data and they form a normal
distribution with a mean of zero. What’s the probability of
getting a positive number from this distribution?
a. 25%
b. 50%
c. 75%
d. We need to calculate the standard deviation and then decide.
39. Which of the following description of distribution is
correct?
a. A Binomial distribution is a probability distribution for
independent events for which there are only two possible
outcomes
b. You cannot use the normal distribution to approximate the
binomial distribution
c. Normal distributions cannot differ in their means and in their
standard deviations.
d. Standard normal distributions can differ in their means and in

13. their standard deviations.
40. A toy factory makes 5,000 teddy bears per day. The
supervisor randomly selects 10 teddy bears from all 5,000 teddy
bears and uses this sample to estimate the mean weight of teddy
bears and the sample standard deviation. How many degrees of
freedom are there in the estimate of the standard deviation?
41. Imagine you have a population of 100,000 cases. For
which of the following degrees of freedom is the closest
estimation of the population parameter?
a. 4
b. 6
c. 10
d. 1000
42. Imagine that the average weight of a total of 500 girls in a
high school is 35kg. Tom randomly sampled 10 girls and
measured their weight. And then he repeated this procedure for
three times. The means and standard deviations are listed as
following. Which sample estimate shows the least sample
variability?
a. Sample one: mean=34, SE=5
b. Sample two: mean=30, SE=2
c. Sample three: mean= 26, SE=3
d. Sample four: mean= 38, SE=5

14. 43. For which of the following degrees of freedom is a t
distribution closest to a normal distribution?
a. 10
b. 20
c. 5
d. 1000
44. In order to construct a confidence interval for the
difference between two means, we are going to assume which of
the followings? (Select all that apply)
a. The two populations have the same variance.
b. The populations are normally distributed.
c. Each value is sampled independently from each other value.
d. The two populations have similar means
45. A researcher tries to compare grades earned on the first
quiz by boys and girls. He randomly chooses 10 students from
boys and 15 students from girls and calculates the confidence
interval on difference between means. How many degrees of
freedom will you get in this t distribution?

15. 46. Which of the following descriptions of the t distribution is
correct? (Select all that apply)
a. With smaller sample sizes, the t distribution is leptokurtic
b. When the sample size is large (more than 100), the t
distribution is very similar to the standard normal distribution
c. With larger sample sizes, the t distribution is leptokurtic
d. The t distribution will never be close to normal distribution
47. _________________refers to whether or not an estimator
tends to overestimate or underestimate a parameter.
______________refers to how much the estimate varies from
sample to sample.
a. Bias; sample variability
b. Sample variability; Bias
c. Mean; standard deviation
d. Standard deviation; Mean
48. Which of the following descriptions of confidence
intervals is correct?
a. Confidence intervals can only be computed for the mean
b. We can only use the normal distribution to compute
confidence intervals
c. Confidence intervals can be computed for various parameters
d. Confidence intervals can only be computed for the population

16. 49. In a histogram, frequencies are represented by_______
a. Lines
b. Bars
c. Portions of the pie
d. Leaves
50. What is the best measure of central tendency for the
following set of numbers? 98,78,56,23,587
a. Mean
b. Mode
c. Median
d. Standard Deviation