The number of customers shopping at a particular store has b

The number of customers shopping at a particular store has been, on average, 25 per day. A new marketing campaign is launched, and the store owner wants to know whether that average has increased. She gathers data over a week in order to test:

H0:25

against the alternative:

HA:>25

The owner uses a significance level of 0.12. The power of the test is 0.80 when = 27.

When = 25, the probability that the owner rejects H0 is ________. Put your answer in decimal form and use two decimal places.

______

When = 27, the probability that the owner fails to reject H0 is _______. Again, two decimals and decimal form.

_____

Solution

The owner uses a significance level of 0.12. The power of the test is 0.80 when = 27.
When = 25, the probability that the owner rejects H0 is ________. Put your answer in decimal form and use two decimal places.

This is rejecting a true null hypothesis (type I error).

Hence, P(type I) = alpha = 0.12 [ANSWER]

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When = 27, the probability that the owner fails to reject H0 is _______. Again, two decimals and decimal form.

This is failing to reject a false null hypothesis, type II error.

Hence,

P(type II) = 1 - power = 1 - 0.80 = 0.20 [ANSWER]