Question

Yes, No    Are Not, Are    Is, Is Not Greater, Less

The mean waiting time at the drive-through of a fast-food restaurant from the time an order is placed to the time the order is received is 84.4 seconds. A manager devises a new drive-through system that she believes will decrease wait time. As a test, she initiates the new system at her restaurant and measures the wait time for 10 randomly selected orders. The wait times are provided in the table to the right. Complete parts (a) and (b) below. 101.2 79.8 67.2 93.1 57.8 85.7 74.3 70.7 64.8 85.4 EClick the icon to view the table of correlation coefficient critical values (a) Because the sample size is small, the manager must verify that the wait time is normally distributed and the sample does not contain any outliers. The normal probability plot is shown below and the sample correlation coefficient is known to be r 0.993. Are the conditions for testing the hypothesis satisfied? the conditions satisfied. The normal probability plot AExpected z-score 2- Vthan the critical value. linear enough, since the correlation coefficient is 1 0- 60 75 90 105 -1- Time (sec) (b) Is the new system effective? Conduct a hypothesis test using the P-value approach and a level of significance of a 0.01 First determine the appropriate hypotheses

Answer 1

from data 10 101.2 79.8 67.2 93.1 57.8 85.7 74.3 70.7 64.8 85.4. 2.) yes the conditions are satisfied. The normal probability ploti's linear is greater than the critical enough, since the correlation coefficient value. bu) Noul Hypothesis (Ho): P1=84.4 Alternate Hypothesis (Hi); M28444 n =10 Mean ž= 780 = 78 Standard deviation sa a X-X)? - 13.54 Test-Statistic i to)= 3- sho (to) = 78-8414 13.54476 pest-Statistic (to) - F1:49]" 1 49 fi degree of freedom any P-value = plt <-1:49) - PO.085 dfa9 E-Front-table f: left-tailed test use the d=0.01 level of significance P-value > significance levella) 0.085 > 0.01 Fail to reject the Null Hypother's (HO) The p-value is greater than the level of significance so there is not sufficient evidence to conclude the new System is effective. option 0