Question

O words Question 21 8 pts A test team takes readings from the miles per gallon (mpg) estimate reading in a new car while driving at 60 mph. The sample consists of 30 readings and has a mean of 31.3 mpg and a standard deviation of 117 mpg. The average mpg of all new cars is 27.6 mpg although the standard deviation is unknown. Is there evidence the new car has superior gas mileage? Conduct a test of significance stating Ho and H, and report the P- value. State your conclusion, setting a = 0.05 HTML Editora B IV AA- IX E 31 x x DE CV OTT: 12pt Tou 30 ... ( A

Answer 1

Given that, x = 31.3,5=11.7,n=30 Null and the alternative hypothesis: H:us 27.6 H:\> 27.6 Significance level, a = 0.05 Test statistic: K- t = S Jn 31.3-27.6 11.7 130 = 1.73 Degree of freedom: n-1= 30-1 = 29 P-value: Use the excel formula, p-value ==TDIST(1.73.29,1) (=TDIST(x,df,tails)) = 0.0471 Decision rule: Reject H,, if p sa otherwise do not reject Ho.

Since the p-value less than the level of significance, so we reject the null hypothesis at specified significance level. Conclusion: There is sufficient evidence to support the claim that new car has superior gas mileage.