Tensile strength tests were performed on two different grades of aluminum spars used in manufacturing the wing of a commercial t
1 answer:
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Answer:
b. 2.333
Step-by-step explanation:
Test if the mean transaction time exceeds 60 seconds.
At the null hypothesis, we test if the mean transaction time is of 60 seconds, that is:
At the alternate hypothesis, we test if it exceeds, that is:
The test statistic is:
In which X is the sample mean, is the value tested at the null hypothesis, s is the standard deviation of the sample and n is the size of the sample.
60 is tested at the null hypothesis:
This means that
A sample of 16 ATM transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds.
This means that
Value of the test statistic:
Thus, the correct answer is given by option b.