1. A random sample of 10 drivers reported the below-average mileage in the city for their...

1. A random sample of 10 drivers reported the below-average mileage in the city for their cars. 18, 21, 24, 25, 25, 25, 25, 26, 29, & 31. The mean of the sample is 24.9 miles per gallon, with an associated standard deviation of about 3.6. Assuming the population mean =3.71. Find the 95% confidence interval for the average mileage of the cars for all of the drivers in the class.

Solutions

Expert Solution

We have given that,

Sample mean =24.9
Sample standard deviation =3.6
Sample size =10
Level of significance=1-0.95=0.05
Degree of freedom =9

t critical value is (by using t table)=   2.2622

Confidence interval formula is

=(22.3247,27.4753)

Therefore, the 95% confidence interval for the average mileage of the cars for all of the drivers in the class =(22.32,27.48)

orchestra answered 1 year ago

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