Question 250466: 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, 217,217, 218, and 218. At the .025 level, has the shelf life of the cake mix increased?
a. yes, becasue computed t is greater than the critical value
b. yes, because computed t is less than the critical value
c. no, because the 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, 217,217, 218, and 218.
At the .025 level, has the shelf life of the cake mix increased?
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Ho: u = 216
H1: u > 216 (Claim)
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I ran a Ttest on the data and got the following results:
test stat = 3.0509
p-value = 0.0079
Comment: This implies the test statistic is higher than
the critical value.
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Conclusion: Since the p-value is less than 0.025 reject Ho.
The shelf life has increased.
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a. yes, becasue computed t is greater than the critical value
b. yes, because computed t is less than the critical value
c. no, because the computed t lies in the region of acceptance.
d. no, because 217.24 is quite close to 216
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Cheers,
Stan H.
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