Multiple
Choice Section (30 points)
1. If all the measurements in a
sample have the value B added to them and then are multiplied by a constant C
then the resulting
A) standard deviation has the
value B added to it and then is multiplied by C
C) mean has the value B added to
it only
D) mean is multiplied by C only
E) none of the above
2. What is the mean of these
numbers: -4, 2, 17, 0, 13, -6,
5, -3?
A) 1
B) 3
C) 6.5
D) 12
3. What is the median of these
numbers -4, 2, 17, 0, 13, -6,
5, -3?
A) 1
B) 3
C) 6.5
D)
12
4. If a distribution of midterm
test scores has a long left hand tail, one might best infer that the test was
A) too
easy, a high number of test takers did well
B) too
hard, relatively few test did well
C)
unreliable
D)
incorrectly administered
E) biased
5. Roll two fair dice, the
probability of getting 4's on both die is
A) 1/36
B) 2/36
C) 1/3
D) 2/3
E) 34/36
6. What does "mutually
exclusive" mean in the context of two chance events?
A) one of
the events must occur, the other may or may not occur
B) when
one event occurs, the other cannot occur
C) both
events must occur
D) the
event with the higher chance must occur
E) None
of the above
7. The most important advantage of
experiments over observational studies is that
A)
experiments are usually easier to carry out.
B)
experiments can give better evidence of causation.
C)
confounding cannot happen in experiments.
D)
an observational study cannot have a response variable.
E)
observational studies cannot use random samples.
8. In comparative trials in medicine, the placebo effect and subconscious bias on the part of the physicians evaluating treatment outcomes can be avoided by using
A) the double-blind
technique.
B) explanatory variables.
C) randomization
D) response variables
E) None of the above
9. You were presented with the
following table and asked to draw a histogram with the data presented in it.
|
(A) |
(B) |
(C) |
(D) |
|
Class |
Frequency |
Relative Frequency |
Cumulative Frequency |
|
0 – 12,000 |
150 |
50% |
50% |
|
12,001 – 15,000 |
90 |
30% |
80% |
|
15,001 – 20,000 |
50 |
16.7% |
96.7% |
|
20,001 – 28,000 |
10 |
3.3% |
100% |
Identify the column that you would
use for the horizontal axis:
(A) Class
(B) Frequency
(C ) Relative Frequency
(D) Cumulative Frequency
(E) None of the above
10. Using the information in
Problem 9, identify the column that you would use for the vertical axis
(A) Class
(B) Frequency
(C ) Relative Frequency
(D) Cumulative Frequency
(E) None of the above
Problem Solving Section (15
points)
11. Ice Cream must be stored at temperatures between -20 and +1 degrees Celsius to remain usable. Suppose all the freezers belonging to a large grocery store chain (like Ralph's or Vons) produce a distribution of storage temperatures that is normal with a mean of -5 degrees Celsius and a standard deviation of 10 degrees Celsius. In other words, the average freezer owned by this grocery store chain keeps food at –5 degrees Celsius. Please answer the following questions about the ice cream being sold to customers.
A. What
percentage of freezers are too warm or too cold to properly store ice cream?
(show your work for full credit) (9 points)
B. What is the value of the inter-quartile
range for this distribution of freezer temperatures? (show your work for full
credit) (6 points)