Written Assignment 12
NAME:
POINTS:
/18
1. (3 points) A student scored
670
on the mathematics part of the SAT. For that par-
ticular exam, the distribution of the scores was normal with mean
514
and standard
deviation
118
. Find the
z
-score of this student.
2. Consider the following set of numbers
98 59 67 68 63 7 93 63 94 17
78 76 15 78 67 46 43 39 82 96
89 27 98 46 21 19 91 77 99 82
(a) (3 points) Find the five-number summary for this block of numbers.
(b) (3 points) Construct a box-and-whiskers plot (boxplot) of the data.
3. (3 points) The heights of women aged
20
to
29
in the United States are approximately
normally distributed with mean
64
:
2
inches and standard deviation
2
:
8
inches. What
is the probability that a womon is taller than
68
inches (
5
foot
8
inches)?
4. (3 points) The heights of men aged
20
to
29
in the United States are approximately
normally distributed with mean
69
:
4
inches and standard deviation
3
:
0
inches. What
is the probability that a man is shorter than
72
inches (
6
foot even)?
5. (3 points) The generic fruit fly is the most studied organism in genetic research be-
cause it is small, is easy to grow, and reproduces rapidly. The length of the thorax
(where the wings and legs attach) in a population of male fruit flies is approximately
Normal with mean
0
:
800
millimeters and standard deviation
0
:
0078
millimeters. What
proportion of male fruit flies have thorax length between
0
:
6
mm and
0
:
9
mm?