In a random sample of 60 computers, the mean repair cost was $150. Assume the population standard deviation is $36. Construct a 90% confidence interval for the population mean.

Question

Mathematics

Winston Mcclure

2 March, 17:20

In a random sample of 60 computers, the mean repair cost was $150. Assume the population standard deviation is $36. Construct a 90% confidence interval for the population mean.

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Answers (1)

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Kate Schwartz · Answer 1

Given that:

x_bar=150, σ=36, n=60

The 90% confidence interval will be found as follows:

+/-1.65 (36/sqrt (60))

=+/-1.65 (4.64758)

=+/-7.6685

Thus our answer will be:

150+/-7.6685

=157.6685 or 142.3315