Many people believe that the average number of Facebook friends is 130. The population standard deviation is 32. A random sample of 50 ASU students revealed that the average number of Facebook friends was 140. At α = 0.01, is there enough evidence to reject the believe that the average number of Facebook friends is 130? Assume that the variable is normally distributed.

Some college graduates employed full-time work more than 40 hours per week, and some work fewer than 40 hours per week. We suspect that the mean number of hours worked per week by college graduates, u, is less than 40 hours and wish to do a statistical test. We select a random sample of college graduates employed full-time and find that the mean of the sample is 35 hours and that the standard deviation is 3 hours. Based on this information, answer the questions below. What are the null hypothesis (H,) and the alternative hypothesis (H,) that should be used for the test? H: u is ? H: u is ? In the context of this test, what is a Type II error? A Type II error is ? fact, u is ? v the hypothesis that u is ? ? v. when, in Suppose that we decide to reject the null hypothesis. What sort of error might we be making? ?

The Weather Underground reported that the mean amount of summer rainfall for the northeastern US is at least 11.52 inches. Ten cities in the northeast are randomly selected and the mean rainfall amount is calculated to be 7.42 inches with a standard deviation of 1.3 inches. At the α = 0.05 level, can it be concluded that the mean rainfall was below the reported average? What if α = 0.01? Assume the amount of summer rainfall follows a normal distribution. Please also state if the assumption of normal distribution was essential for solving this question. You will need to specify the appropriate hypothesis, identify the statistical test, estimate p-value (using R command), and state your conclusion in the context of the problem. For the conclusion, please use the following template. If you reject the null writeSince p-value is [write the value of your p-value] and is less than [write the value of alpha inpercent] we reject the null hypothesis at [write the value of alpha]% significance…

The mean SAT score in mathematics is 588. The standard deviation of these scores is 47. A special preparation course claims that it's graduates will score higher on average than the mean score 588. A random sample of 150 students completed the course, and their mean SAT score in mathematics was 591. At the 0.1 level of significance,can we conclude that the preparation course does what it claims? Assume that the standard deviation is also 47. Perform a one tailed test

Suppose the length of human pregnancies from conception to birth varies according to a distribution that is normal with mean of 266 days and standard deviation of “alpha”. 11.7% of pregnancies last 284 days or more, find the variance of the distribution .

The mean SAT score in mathematics, u, is 596. The standard deviation of these scores is 47. A special preparation course clalms that its graduates will score higher, on average, than the mean score 596. A random sample of 90 students completed the course, and their mean SAT score in mathematics was 608. At the 0.05 level of significance, can we condude that the preparation course does what it claims? Assume that the standard deviation of the scores of course graduates is also 47. Perform a one-talled test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H,. H, :0 H, :0 (b) Determine the type of test statistic to use. OSO (Choose one) ▼ (c) Find the value of the test statistic. (Round to three or more decimal places.) (d) Find the critical value. (Round to three or more decimal…

In a random sample of 6 cell phones, the mean full retail price was 517.30 and standard deviation is 184.00. Further research suggests that the population mean is 425.73. Does the t-value for the original sample fall between -t0.99 and t0.99?