5E.
Examination 1.
Fall 2009
Prof. Tashman
SCORING BREAKDOWN
Q
1a
1b
1c
2a
2b
3a
3b
3c
4
5a
5b
5c
6a
6b
Points
4
5
4
5
5
4
5
4
10
3
5
3
3
4
Earned
Q
7a
7b
8a
8b
8c
8d
9a
9b
ExtraI
ExtraII
Total (incl Extra)
Points
5
5
3
3
4
4
6
6
2
2
104
Earned
1.
The following table shows the probability distribution of a random variable X:
X
0
1
2
3
f(x)
0.2
0.3
0.1
0.4
Compute a) E(X)
(4pts)
b) var(X)
(5pts)
c) SD(X)
(4pts)
2.
The probability of rain on Saturday is 0.75.
The probability of rain on Sunday is 0.20.
The
probability of rain on both days is 0.05.
a) What is the probability of rain on Sat or Sun?
(5pts)
b)
What is the probability of rain neither day?
(5pts)
3.
A math honor society has 15 members, and four members are randomly selected to form a
committee.
The roles of each committee member are to be identical.
a)
How many such committees can be formed?
(4pts)
b)
Suppose Greg and Loren are members of the honor society.
What is the probability that
neither Greg nor Loren is chosen for the committee?
(5pts)

This
** preview**
has intentionally

**sections.**

*blurred***to view the full version.**

*Sign up*
This is the end of the preview.
Sign up
to
access the rest of the document.