# statistics

posted by George

An auto maker estimates that the mean gas mileage of its sport utility vehicle is 20 miles per gallon. A random sample of 8 such vehicles had a mean of 18 per gallon and a standard deviation of 5 miles per gallon. At á=0.05, can you reject the auto maker’s claim that the mean gas mileage of its sports
utility vehicle is 20 miles per gallon? Assume the population is normally distributed.

1. MathGuru

You can use a t-test for this problem since the sample size is small.

Using your data in the formula:
t = (18 - 20)/(5/√8) = ?

Finish the calculation.

Using a t-table at 0.05 level of significance for a two-tailed test (the test is two-tailed because the alternative hypothesis would not specify a direction) at 7 degrees of freedom (df = n - 1 = 8 - 1 = 7), find your critical or cutoff value to reject the null. If the t-test statistic calculated above does not exceed the critical value you found in the t-table, you cannot reject the null. If the t-test statistic exceeds the critical value from the t-table, reject the null.

I hope this will help get you started.

2. sara

of 500 employee ,200 participating i n companies profit sharing plan (p),250 having major medical insurance coverage (m) and 50 find the probibility +will not be participant in either program

3. sara

of 500 employee ,200 participating i n companies profit sharing plan (p),250 having major medical insurance coverage (m) and 50 participated in both program
find the probibility will not be participant in either program

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