| 
 
 
| Question 230204:  A manufacturer wants to increase the shelf life of a line of cake mixes. Past records indicate that the average shelf life of the mix is 216 days. After a revised mix has been developed, a sample of nine boxes of cake mix gave these shelf lives (in days): 215, 217, 218, 219, 216, 217, 218 and 218, At the 0.025 level, has the shelf live of the cake mix increased?
 A. Yes, because computed t is greater than the critical value.
 B. Yes, because computed t is lss than the critical value.
 C. No, because computed t lies in the region of acceptance.
 D. No, because 217.24 is quite close to 216.
 Answer by stanbon(75887)
      (Show Source): 
You can put this solution on YOUR website! A manufacturer wants to increase the shelf life of a line of cake mixes. Past records indicate that the average shelf life of the mix is 216 days. After a revised mix has been developed, a sample of nine boxes of cake mix gave these shelf lives (in days): 215, 217, 218, 219, 216, 217, 218 and 218, At the 0.025 level, has the shelf live of the cake mix increased? ---
 I ran a Ttest on a TI calculator and got the following results:
 test statistic: t = 2.7584
 p-value = 0.0141
 Since the p-value is less that 2.5%, reject Ho.
 ----------------------------------------------------------
 Ans: A
 --------------------
 Cheers,
 Stan H.
 A. Yes, because computed t is greater than the critical value.
 B. Yes, because computed t is less than the critical value.
 C. No, because computed t lies in the region of acceptance.
 D. No, because 217.24 is quite close to 216.
 
 | 
  
 | 
 |