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IE 121 – Spring 2002
Midterm exam 2
1. (15 points) In this problem, you need to select the correct answer.
1. The null hypothesis is
H
0
:
μ
=
μ
0
, and the variance of the population is
known. Which test statistic has to be used for the hypothesis testing?
a)
z
0
b)
t
0
c)
χ
2
0
2. Let
L
95
be the length of the 95% conﬁdence interval for a certain mean.
Let
L
90
be the length of the 90% conﬁdence interval for the same mean.
Which of the following statements is true?
a)
L
95
> L
90
b)
L
95
< L
90
c)
L
95
=
L
90
3. Suppose we want to test the null hypothesis on the population pro
portion
H
0
:
p
=
p
0
against the alternative one
H
1
:
p > p
0
at the
signiﬁcance level
α
. Which of the following is the correct rejection cri
terion?
a)

z
0

> z
α/
2
b)
z
0
> z
α
c)
z
0
<

z
α
d)
z
0
> z
α/
2
4. When the number of degrees of freedom of the
t
distribution is very
large, it becomes:
a) a normal distribution with mean 0 and variance 2
b) a
χ
2
distribution
c) the standard normal distribution
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This test prep was uploaded on 02/26/2008 for the course IE 121 taught by Professor Perevalov during the Spring '08 term at Lehigh University .
 Spring '08
 Perevalov

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