Question

In: Statistics and Probability

A survey of 77 commercial airline flights of under 2 hours resulted in a sample average...

A survey of 77 commercial airline flights of under 2 hours resulted in a sample average late time for a flight of 2.60 minutes. The population standard deviation was 12 minutes. Construct a 95% confidence interval for the average time that a commercial flight of under 2 hours is late. What is the point estimate? What does the interval tell about whether the average flight is late?

(Round your answers to 2 decimal places.)

≤ μ ≤


The point estimate is

.

Solutions

Expert Solution

Solution :

Given that,

Point estimate = sample mean = = 2.60

Population standard deviation = = 12

Sample size = n = 77

Z/2 = 1.96

Margin of error = E = Z/2* ( /n)

= 1.96 * ( 12 / 77)

Margin of error = E = 2.68

At 95% confidence interval estimate of the population mean is,

- E + E

2.60 - 2.68 2.60 + 2.68

-0.08 5.28

( -0.08 , 5.28)

orchestra answered 3 years ago
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