Facebook: A study showed that two years ago, the mean time spent per visit to Facebook was20.2

minutes.Assume the standard deviation is=

4.0

minutes.Suppose that a simple random sample of107

visits was selected this year and has a sample mean of=

x

19.2

minutes.A social scientist is interested to know whether the mean time of Facebook visitshas decreased.Use the=

0.10

level of significance and theP-valuemethod with theTI-84calculator.

(a) State the appropriate null and alternate hypotheses.

(b) Compute theP-value.

(c) State a conclusion. Use the=

0.10

level ofsignificance.

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Part 1 of 4

(a) State the appropriate null and alternate hypotheses.H

0

:

H

1

:

This hypothesis test is a

(Choose one)

test