## According to a Pew Research Center study, in May 2011, 35% of all American adults had a smart phone (one which the user can use to read emai

According to a Pew Research Center study, in May 2011, 35% of all American adults had a smart phone (one which the user can use to read email and surf the Internet). A communications professor at a university believes this percentage is higher among community college students.

She selects 300 community college students at random and finds that 120 of them have a smart phone. In testing the hypotheses H0: p = 0.35 versus Ha: p > 0.35, she calculates the test statistic as Z = 1.82. Assume the significance level is ? = 0.10.

Which of the following is an appropriate conclusion for the hypothesis test?

There is enough evidence to show that more than 35% of community college students own a smart phone (P?value = 0.034).

There is enough evidence to show that more than 35% of community college students own a smart phone (P?value = 0.068).

There is not enough evidence to show that more than 35% of community college students own a smart phone (P?value = 0.966).

There is not enough evidence to show that more than 35% of community college students own a smart phone (P?value = 0.034).

Does secondhand smoke increase the risk of a low weight birth? A baby is “low birth weight” if it weighs less than 5.5 pounds at birth. According to the National Center of Health Statistics, about 7.8% of all babies born in the U.S. are categorized as low birth weight. Researchers randomly select 1200 babies whose mothers had extensive exposure to secondhand smoke during pregnancy. 10.4% of the sample are categorized as low birth weight.

Answer the following:

Which of the following are the appropriate null and alternative hypotheses for this research question.

H0: p = 0.078; Ha: p ? 0.078

H0: p = 0.078; Ha: p > 0.078

H0: p = 0.104; Ha: p ? 0.104

H0: ? = 0.104; Ha: ? > 0.104

## Answers ( )

Answer:So the p value obtained was a very low value and using the significance level given we have so we can conclude that we have enough evidence to reject the null hypothesis

And the best conclusion would be:

There is enough evidence to show that more than 35% of community college students own a smart phone (Pvalue = 0.034).

And for the second case the correct system of hypothesis is:

H0: p = 0.078; Ha: p > 0.078

Step-by-step explanation:Data given and notationn=300 represent the random sample taken

estimated proportion of college students that have a smart phone

is the value that we want to test

represent the significance level

Confidence=90% or 0.90

z would represent the statistic (variable of interest)

represent the p value (variable of interest)

Concepts and formulas to useWe need to conduct a hypothesis in order to test the claim that the proportion is >0.35.:

Null hypothesis:

Alternative hypothesis:

When we conduct a proportion test we need to use the z statistic, and the is given by:

(1)

The

One-Sample Proportion Testis used to assess whether a population proportion is significantly different from a hypothesized value .Calculate the statisticSince we have all the info requires we can replace in formula (1) like this:

Statistical decisionIt’s important to refresh the

p value method or p value approach. “This method is about determining “likely” or “unlikely” by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed”. Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.The significance level provided . The next step would be calculate the p value for this test.

Since is a right tailed test the p value would be:

So the p value obtained was a very low value and using the significance level given we have so we can conclude that we have enough evidence to reject the null hypothesis

And the best conclusion would be:

There is enough evidence to show that more than 35% of community college students own a smart phone (Pvalue = 0.034).

And for the second case the correct system of hypothesis is:

H0: p = 0.078; Ha: p > 0.078