A report states that adults 18- to 24- years-old send andreceive 128 texts every day. Suppose we take a sample of 25- to 34-year-olds to see if their mean number of daily texts differs fromthe mean for 18- to 24- year-olds.
(a) State the null and alternative hypotheses we should use totest whether the population mean daily number of texts for 25- to34-year-olds differs from the population daily mean number of textsfor 18- to 24-year-olds. (Enter != for ? as needed.)
H0:
Ha:
(b) Suppose a sample of thirty 25- to 34-year-olds showed asample mean of 118.9 texts per day. Assume a population standarddeviation of 33.17 texts per day.
Compute the p-value. (Round your answer to four decimalplaces.)
p-value =
(c) With ? = 0.05 as the level of significance, what isyour conclusion?
(d) Repeat the preceding hypothesis test using the criticalvalue approach.
State the null and alternative hypotheses. (Enter != for ? asneeded.)
H0:
Ha:
(e) Find the value of the test statistic. (Round your answer totwo decimal places.)
State the critical values for the rejection rule. (Use? = 0.05. Round your answer to two decimal places. If thetest is one-tailed, enter NONE for the unused tail.)
test statistic?
test statistic?
(f)
State your conclusion.
Do not reject H0. We cannot conclude thatthe population mean daily texts for 25- to 34-year-olds differssignificantly from the population mean of 128 daily texts for 18-24-year-olds.
Reject H0. We cannot conclude that thepopulation mean daily texts for 25- to 34-year-olds differssignificantly from the population mean of 128 daily texts for 18-24-year-olds.
Do not reject H0. We can conclude that thepopulation mean daily texts for 25- to 34-year-olds differssignificantly from the population mean of 128 daily texts for 18-24-year-olds.
Reject H0. We can conclude that thepopulation mean daily texts for 25- to 34-year-olds differssignificantly from the population mean of 128 daily texts for 18-24-year-olds.
