2.A random sample of 190 cars found that 89% had an automatic transmission. Find and interpret the 95% confidence interval for the true proportion of cars that are automatic. 3.In a recent study of 50American adults, it was found that they drove 16 miles to work with a standard deviation of 2.5 miles. a)Construct and interpret the 80% confidence interval for the average distance people drive to work every day .b)Does your answer change if you know the national standard deviation for miles driven isactually2.5? If so, find the new confidence interval, if not, explain why. c)Suppose a previous
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2.A random sample of 190 cars found that 89% had an automatic transmission. Find and interpret the 95% confidence interval for the true proportion of cars that are automatic.
3.In a recent study of 50American adults, it was found that they drove 16 miles to work with a standard deviation of 2.5 miles.
a)Construct and interpret the 80% confidence interval for the average distance people drive to work every day
.b)Does your answer change if you know the national standard deviation for miles driven isactually2.5? If so, find the new confidence interval, if not, explain why.
c)Suppose a previous study done in 2000 showed an average commute distance of 15mileswith st dev 3.2 miles; treat these values as population data. Is there sufficient evidence to show that the drive distances have increased? Use ?=.04. Consider the implications and the practical significance of your findings.
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