Quiz 1 – In Lab Review (W08)
1.
“Statistical thinking will someday be as necessary to
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
as the ability to read and write.
H. G. Wells (18661946)
2 
Class A vs B
:
An instructor teaches two classes, Class A and Class B (40 students each). The frequency plots for
the quiz scores are given below. You find a quiz of a student, but notice they did not circle which class they are in.
You will use his/her quiz score to make a decision about the following hypotheses.
H
0
: The student is from Class A.
H
1
: The student is from Class B.
X
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X
0
1
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10
0
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10
Quiz Score
Quiz Score
a)
What is the direction of extreme for this test?
1sided to the L
1sided to the R
2sided
b)
Suppose the decision rule were to reject Ho if X = 0 or X = 10. If so, the value of alpha = . . . . . . . . .
c)
That value of alpha represents the probability of a
mistake
, namely concluding the quiz is from Class A
w
h
e
n
i
n
f
a
c
t
,
i
t
w
a
s
f
r
o
m
C
l
a
s
s
B
.
True
False
d)
Also, you can calculate beta, the probability of a type 2 error. Here,
β
= . . . . . . .
3  The data in Study X was not statistically significant at the 5% level. Which of the following pvalues
could apply?
(Circle all that apply)
0.007
0.041
0.098
0.151
4
 Stat 100 Students
: For many years, we’ve assumed that only 5% of the Stat 100 students take another
statistics class. The Statistics Department believes that this value is too low and decides to take a sample of 20
students out of the 355 students that took Statistics 100 (F05) and determine if they continued their statistical
education.
a)
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 Winter '08
 Veneable
 Statistics, Statistical hypothesis testing, class a, new treatment, score sheet, Categorical Categorical Categorical

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