According to Facebook’s self-reported statistics, the average Facebook user has
ID: 3359733 • Letter: A
Question
According to Facebook’s self-reported statistics, the average Facebook user has 130 Facebook friends. For a statistics project a student at Contra Costa College tests the hypothesis that CCC students will average more than 130 Facebook friends.
She randomly selects 3 classes from the schedule of classes and distributes a survey in these classes. Her sample contains 45 students.
Here are the null and alternative hypotheses for her study: H0: µ = 130, Ha: µ > 130.
1. What does µ represent in these hypotheses?
mean number of Facebook friends for the average user
mean number of Facebook friends for the CCC students in her sample
mean number of Facebook friends for CCC students
2. From her survey data, the statistics student calculates that the mean number of Facebook friends for her sample is 138.7 with a standard deviation of 79.3. She analyzed her data using a t-test and obtained a P-value of 0.23.
What conclusion can she draw from her data?
a.Nothing. The conditions for use of a t-test were not met. She cannot trust that the P-value is accurate for this reason.
b. Even though 138.7 is larger than 130, it is not significantly larger than 130. In other words, the data do not provide enough evidence to conclude that the mean number of Facebook friends of all CCC college students is higher than 130.
c. 138.7 is significantly larger than 130. In other words the data provide provide enough evidence to conclude that the mean number of Facebook friends of all CCC college students is higher than 130.
3. According to Facebook’s self-reported statistics, the average Facebook user is connected to 80 community pages, groups, and events. For a statistics project a student at Contra Costa College tests the hypothesis that CCC students will average less than 80 such connections.
She posts a survey on her Facebook page. Her sample contains 45 responses.
She chooses a 5% level of significance. From her data she calculates a t-test statistic of approximately -1.74 with a P-value of about 0.04.
What can she conclude?
a. Nothing. The conditions for use of a T-model are not met. She cannot trust that the P-value is accurate for this reason.
b. The data is not statistically significant. In other words, the data do not provide enough evidence to conclude that the mean number of Facebook connections to community pages, groups and events of all CCC college students is less the 80.
c. The data is statistically significant. In other words, the data do provide enough evidence to conclude that the mean number of Facebook connections to community pages, groups and events of all all CCC college students is less the 80.
Explanation / Answer
1 ans) mean number of Facebook friends for CCC students
because
the population of intrest is ccc students so mu is the mean number dacebook friends for this population
2 ans) b . Even though 138.7 is larger than 130, it is not significantly larger than 130. In other words, the data do not provide enough evidence to conclude that the mean number of Facebook friends of all CCC college students is higher than 130.
because pvalue is 0.23 the difference of 8.7 friends (138.7 mu 130) is not stastically significantly
3 ANS) a. Nothing. The conditions for use of a T-model are not met. She cannot trust that the P-value is accurate for this reason.
AS She didnot take a random sample of ccc students so she couldnot conduct the test
how ever if the sample was random you have right conclusion based on the p value
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