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Quiz 10
You scored 100 out of 100
Question 1
Your answer is CORRECT.
The z-score associated with the 97.5 percent confidence interval is
a)
2.160
b)
1.900
c)
2.241
d)
2.744
e)
1.960
f)
None of the above

Question 2
Your answer is CORRECT.
What will increase the width of a confidence interval?

Question 3
Your answer is CORRECT.
A simple random sample of 64 8th graders at a large suburban middle school indicated
that 88% of them are involved with some type of after school activity. Find the margin
of error associated with a 98% confidence interval that estimates the proportion of
them that are involved in an after school activity.

c)
0.094
d)
0.083
e)
0.041
f)
None of the above
Question 4
Your answer is CORRECT.
A simple random sample of 49 8th graders at a large suburban middle school indicated
that 89% of them are involved with some type of after school activity. Find the 95%
confidence interval that estimates the proportion of them that are involved in an after
school activity.

Question 5
Your answer is CORRECT.
Mars Inc. claims that they produce M&Ms with the following distributions:
Brown
30% Red
20% Yellow
Orange 10% Green 10% Blue
A bag of M&Ms was randomly selected from the grocery store shelf, and the color
counts were:
Brown
22 Red
22 Yellow
Orange 12 Green 15 Blue
Find the 95% confidence interval for the proportion of yellow M&Ms in that bag.
20%
10%
22
15