A local church parish wants to raise money to add to their campus. In a sample from a previous fund raising campaign, the parish found that of the 134 people in the sample they contacted, that 70 actually contributed money. Of those that contributed money, the average contribution was $865 with a standard deviation of $215. In the recent fundraising campaign, a sample of 91 people revealed that 50 have contributed money with an average contribution of $1159 and a standard deviation of $336. When testing (at the 5% level of significance) whether the variance of the contributions has increased in the current campaign compared to the previous campaign, what is the test statistic? (please round your answer to 2 decimal places)

Statewide, the population as a whole watches 6.2 hours of TV per day. A random sample of 1017 senior citizens in the state reports watching an average of 5.9 hours per day, with a standard deviation of 0.7. is the difference significant

A second species of extra-terrestrial has a mean height of 71cm and a standard deviation of 5.3cm. An astro biologist discovers that 30% of the extra-terrestrials bump their heads when they enter their spacecraft. What is the height of the door to the space craft?

A local church parish wants to raise money to add to their campus. In a sample from a previous fund raising campaign, the parish found that of the 139 people in the sample they contacted, that 68 actually contributed money. Of those that contributed money, the average contribution was $898 with a standard deviation of $268. In the recent fundraising campaign, a sample of 90 people revealed that 52 have contributed money with an average contribution of $1,118 and a standard deviation of $354. When testing (at the 5% level of significance) whether the average amount contributed has increased in the current campaign compared to the previous campaign, what is the test statistic? (please round your answer to 2 decimal places)

Salvatore, as the director of a regional bank, is concerned about the wait times of customers at the four branches. He randomly selects 48 patrons at each branch and records the waiting time for each patron. The results of the samples are shown below. The Alvrine branch has a mean waiting time of 13.49 minutes with a standard deviation of 1.97 minutes.The Durham branch has a mean waiting time of 12.61 minutes with a standard deviation of 2.89 minutes.The Hanover branch has a mean waiting time of 11.06 minutes with a standard deviation of 2.46 minutes.The Mascomonet branch has a mean waiting time of 12.89 minutes with a standard deviation of 3.12 minutes.

A luxury furniture manufacture will make custom furniture for their customers. Pricing is based on the number of hours of skilled labor it takes to make a piece. The time it takes to make a custom couch is normally distributed with an average of 280 hours and a standard deviation of 40 hours.     What percent of custom couches take 255 hours or less to make?        How long would it take to build a couch that is in the 95th percentile?

Ann recently switched her primary doctor to one specializing in caring for elderly patients. On her new doctor's website, it says that the mean systolic blood pressure among elderly females is 120 millimeters of mercury ( mmHg ). Ann believes the value is actually higher. She bases her belief on a recently reported study of 10 randomly selected, elderly females. The sample mean systolic blood pressure was 128 mmHg , and the sample standard deviation was 25 mmHg . Assume that the systolic blood pressures of elderly females are approximately normally distributed. Based on the study, at the 0.10 level of significance, can it be concluded that μ , the population mean systolic blood pressure among elderly females, is greater than 120 mmHg ?   Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places. (If necessary, consult a list of formulas.) (a) State the null hypothesis H0 and the…

Amanda recently switched her primary doctor to one specializing in caring for elderly patients. On her new doctor's website, it says that the mean systolic blood pressure among elderly females is 115 millimeters of mercury (mmHg). Amanda believes the value is actually higher. She bases her belief on a recently reported study of 17 randomly selected, elderly females. The sample mean systolic blood pressure was 123 mmHg, and the sample standard deviation was 23 mmHg. Assume that the systolic blood pressures of elderly females are approximately normally distributed. Based on the study, at the 0.05 level of significance, can it be concluded that μ, the population mean systolic blood pressure among elderly females, is greater than 115 mmHg? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places.  A. Find the value of the test statistic and round to 3 or more decimal places. (I have posted a picture of an example problem…

The mean finish time for a yearly amateur auto race was 186.84 minutes with a standard deviation of 0.327 minute. The winning car, driven by Dan, finished in 186.48 minutes. The previous year's race had a mean finishing time of 112.4 with a standard deviation of 0.125 minute. The winning car that year, driven by Beth, finished in 112.14 minutes. Find their respective z-scores. Who had the more convincing victory? Dan had a finish time with a z-score of Beth had a finish time with a z-score of (Round to two decimal places as needed.)

The average 20-to 29-year-old man is 69.6 inches tall, with a standard deviation of 3.0 inches, while the average 20-to 29-year-old woman is 64.1 inches tall, with a standard deviation of 3.8 inches. Who is relatively taller, a 67-inch man or a 62-inch woman?