Question

An automobile manufacturer calms that their van has a 40.6 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this van. After testing 27 vans they found a mean MPG of 40.2 with a standard deviation of 2.1. Is there sufficient evidence at the 0.05 level that the vans underperform the manufacturer's MPG rating? Assume the population distribution is approximately normal Step 2 of 5: Find the value of the test statistic. Round your answer to three decimal places. AnswerHow to Enter) 1 Point m Tables Keypad Keyboard Shortcuts < Ne Prev

Answer 1

The test statistic formula is given as below:

t = (Xbar - µ)/[S/sqrt(n)]

From given data, we have

µ = 40.6

Xbar = 40.2

S = 2.1

n = 27

t = (Xbar - µ)/[S/sqrt(n)]

t = (40.2 - 40.6)/(2.1/sqrt(27))

t = -0.98974

Test statistic = -0.990