Question

Question 1 of 8 According to recent statistics, the average Facebook user has 225 Facebook friends. For a statistics project a student at San Jose State College tests the hypothesis that SJSU students will average more than 225 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 = 255, Ha: µ > 255. What does µ represent in these hypotheses?

-Even though 240.2 is larger than 225, it is not significantly larger than 225. In other words, the data do not provide enough evidence to conclude that the mean number of Facebook friends of all SJSU college students is higher than 225.

-Nothing. The conditions for use of a t-test were not met. She cannot trust that the P-value is accurate for this reason.

-240.2 is significantly larger than 225. In other words the data provide provide enough evidence to conclude that the mean number of Facebook friends of all SJSU college students is higher than 225.

Question 2 of 8 From her survey data, the statistics student calculates that the mean number of Facebook friends for her sample is 240.2 with a standard deviation of 79.3. She analyzed her data using a t-test and obtained a P-value of p = .10
What conclusion can she draw from her data?

-Even though 240.2 is larger than 225, it is not significantly larger than 225. In other words, the data do not provide enough evidence to conclude that the mean number of Facebook friends of all SJSU college students is higher than 225.

-Nothing. The conditions for use of a t-test were not met. She cannot trust that the P-value is accurate for this reason.

-240.2 is significantly larger than 225. In other words the data provide provide enough evidence to conclude that the mean number of Facebook friends of all SJSU college students is higher than 225.

Question 3 of 8 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 San Jose State University tests the hypothesis that SJSU 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 -2.14 with a P-value of about 0.019. What can she conclude?

-Nothing. The conditions for use of a T-model are not met. She cannot trust that the P-value is accurate for this reason.

-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 SJSU college students is less the 80.

-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 SJSU college students is less the 80

Question 4 of 8 The average US woman wears 515 chemicals on an average day from her makeup and toiletries. A random sample from California found that on average the California woman wears 325 chemicals per day with a standard deviation of 90.5.
Which hypothesis test should be used to determine whether the sample contains less than the US average of wearing 515 chemicals per day?

- t-test for the population mean

- z-test for the population mean

- z-test for the population proportion

- t-test for the population proportion

Answer 1

Question 1 of 8

Since student at San Jose State College tests the hypothesis that SJSU students will average more than 225 Facebook friends, µ represents:

mean number of Facebook friends for SJSU students

Question 2 of 8

Since p-value is larger than 0.05, we cannot reject null hypothesis. Therefore, correct option is:

Even though 240.2 is larger than 225, it is not significantly larger than 225. In other words, the data do not provide enough evidence to conclude that the mean number of Facebook friends of all SJSU college students is higher than 225.

Question 3 of 8

Since p-value is less than 0.05, we reject the null hypothesis. Therefore, correct option is:

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 SJSU college students is less the 80.

Question 4 of 8

Since we want to compare mean and population standard deviation is unknown, the correct option is:

t-test for the population mean