Question

According to a report, Americans watch television each weekday for an average of 151 minutes last year with a population standard deviation of 30 minutes. A recent sample of 120 American adults showed that they watch television weekday for an average of 162 minutes. Test the current average time spent watching television each weekday by American adults is longer than 151 minutes at a 10% level of significance.

Answer 1

X→ television watching time

We have given

Population Mean (u)= 151

Population standard deviation (Sigma)=30

Sample size n=120

Xbar= 162

Standard error (se)= 30/√120= 2.738613

Setting up hypothesis:

Ho: u=151

H1:u>151

Level of significance (alpha)= 0.10

Test statistic z= (xbar-u)/(s.e)=(162-151)/2.738613=4.0166

P value=prob(z>4.0166)=0.00

Since p value is less than 0.10(level of significance),we Reject the null hypothesis.

Conclusion: we have sufficient evidence to claim that the television watching is more tha 151 minutes at each weekday.

Thanks!

Stay safe!