In quality-control applications of hypothesis testing, the null and alternative hypotheses are frequently specified as H0: The production process is performing satisfactorily. Ha: The production process is performing unsatisfactorily. Accordingly, α is sometimes referred to as the producer's risk while β is called the consumer's risk. An injection molded produces plastic golf tees. The process is designed to produce tees with a mean weight of .252 ounce. To investigate whether the injection molded is operating satisfactorily, 40 tees were randomly sampled from the last hour's production.
Table of golf tee weights
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0.246
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0.253
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0.251
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0.250
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0.256
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0.251
|
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0.252
|
|
0.247
|
|
0.249
|
|
0.251
|
|
0.254
|
|
0.252
|
|
0.253
|
|
0.251
|
|
0.252
|
|
0.251
|
|
0.250
|
|
0.255
|
|
0.253
|
|
0.253
|
|
0.251
|
|
0.249
|
|
0.251
|
|
0.251
|
|
0.252
|
|
0.251
|
|
0.249
|
|
0.249
|
|
0.249
|
|
0.252
|
|
0.249
|
|
0.253
|
|
0.252
|
|
0.251
|
|
0.248
|
|
0.252
|
|
0.253
|
|
0.249
|
|
0.251
|
|
0.249
|
What is the value of the test statistic?
Z=
(Round to two decimal places)
What is the rejection region using .01? Choose the correct answer below.
- z>1.96
- z>1.96
- z<-1.96
- z<-1.96 or z>1.96
- z<-2.575
- z<-2.575 or z> 2.575