IMathAS-libretexts

6.15 Browsing on the mobile device: A 2012 survey of 2,254 American adults indicates that 17% of cell phone owners do their browsing on their phone rather than a computer or other device.

(a) According to an online article, a report from a mobile research company indicates that 38 percent of Chinese mobile web users only access the internet through their cell phones. Conduct a hypothesis test to determine if these data provide strong evidence that the proportion of Americans who only use their cell phones to access the internet is different than the Chinese proportion of 38%.
The hypotheses for this test are:

Ho: p = .38
Ha: p < .38
Ho: p = .38
Ha: p ≠ .38
Ho: p = .38
Ha: p > .38

The test statistic is: (please round to two decimal places) The p-value is: (please round to four decimal places) (b) The result of the hypothesis test is:

Since p ≥ α we do not have enough evidence to reject the null hypothesis
Since p ≥ α we accept the null hypothesis
Since p<α we reject the null hypothesis and accept the alternative
Since p ≥ α we reject the null hypothesis and accept the alternative
Since p<α we fail to reject the null hypothesis

Interpret the result in the context of this study.

The data provide significant evidence that the proportion of Americans who use their cell phones to access the internet is different than the Chinese proportion
The data do not provide significant evidence that the proportion of Americans who use their cell phones to access the internet is different than the Chinese proportion

(c) Calculate a 95% confidence interval for the proportion of Americans who access the internet on their cell phones, and interpret the interval in this context.
lower bound: (please round to four decimal places)
upper bound: (please round to four decimal places) Interpret the confidence interval in the context of the study:

We can be 95% confident that our confidence interval contains the sample proportion of Americans who use their cell phones to access the internet
We can be 95% confident that the proportion of Americans who use their cell phones to access the internet is contained within our confidence interval
95% of Americans use their cell phone to access the internet

License