Question
A study of the ages of motorcyclists killed in crashes involves the random selection of 149...
A study of the ages of motorcyclists killed in crashes involves the random selection of 149 drivers with a mean of 33.24years. Assuming that sigmaσequals=8.2 years, construct and interpret a 90% confidence interval estimate of the mean age of all motorcyclists killed in crashes.
Homework Answers
Answer #1
Solution :
Given that,
Z
/2
= 1.645
Margin of error = E = Z/2*
(
/
n)
= 1.645 * (8.2 /
149)
= 1.11
At 90% confidence interval estimate of the population mean is,
- E < 
<
+ E
33.24 - 1.11 <
< 33.24 + 1.11
32.13 <
< 34.35
(32.13 , 34.35)
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