A pizza delivery chain advertises that it will deliver your pizza in 40 minutes from when the order is placed. Being a skeptic. you decide to test and see if the mean delivery time is actually more than 40 minutes. For the simple random sample of 6 customers who record the amount of time it takes for each of their pizzas to be delivered, the mean is 48.2 minutes with a standard deviation of 10.6 minutes. Assume that the population distribution is approximately normal. Perform a hypothesis test using a 0.10 level of significance.

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 37 randomly selected people who train in groups, and finds that they run a mean of 47.7 miles per week. Assume that the population standard deviation for group runners is known to be 3.3 miles per week. She also interviews a random sample of 49 people who train on their own and finds that they run a mean of 49.4 miles per week. Assume that the population standard deviation for people who run by themselves is 4.4 miles per week. Test the claim at the 0.10 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

Two friends, Karen and Jodi, work different shifts for the same ambulance service. They wonder if the different shifts average different numbers of calls. Looking at past records, Karen determines from a random sample of 32 shifts that she had a mean of 4.8 calls per shift. She knows that the population standard deviation for her shift is 1.4 calls. Jodi calculates from a random sample of 40 shifts that her mean was 4.2 calls per shift. She knows that the population standard deviation for her shift is 1.1 calls. Test the claim that there is a difference between the mean numbers of calls for the two shifts at the 0.01 level of significance. Let Karen's shifts be Population 1 and let Jodi's shifts be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

Assume that the average weight of an NFL player is 245.7 lbs with a standard deviation of 34.5 lbs. The distribution of NFL weights is not normal. Suppose you took a random sample of 32 players. What is the probability that the sample average will be less than 260 lbs?

Loretta, who turns 91 this year, has heard that the mean systolic blood pressure among the elderly is 120 millimeters of mercury (mm Hg), but she believes that the actual value is higher. She bases her belief on a recently reported study of 19 randomly selected, elderly adults. The sample mean systolic blood pressure of the adults in the study was 121 mm Hg , and the sample standard deviation was 20 mm Hg. Assume that the population of systolic blood pressures of elderly adults is normally distributed. Based on the study, at the 0.1 level of significance, can it be concluded that μ , the mean systolic blood pressure among elderly adults, is greater than 120 mm Hg? Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (a) State the null hypothesis H0? and the alternative hypothesis H1? . H0:? H1:? (b) Determine the type of test statistic to…

Cody took his first physics exam and scored an 80. The population mean for this exam is 70, and the standard deviation is 5. What is the probability of selecting a person with a score greater than Cody’s?

The weight of garbage produced per household per week has an average value of approximately 9.3 pounds. The standard deviation of garbage per household per week has been measured to be 2.7 pounds. You have a garbage hauling company and need to know the probability of hauling heavy loads of garbage. How would you calculate the probability that your company will be hauling garbage loads greater than 12 pounds per household during a weekly pick-up? probability. Set up your calculation correctly. You DO NOT need to calculate the

On average, a banana will last 6.5 days from the time it is purchased in the store to the time it is too rotten to eat. Is the mean time to spoil different if the banana is hung from the ceiling? The data show results of an experiment with 11 bananas that are hung from the ceiling. Assume that that distribution of the population is normal. 5.3, 6, 5.5, 7, 5.4, 5.7, 6.2, 6.4, 9.1, 8.7, 8.3 What can be concluded at the the a = 0.01 level of significance level of significance? a. For this study, we should use Select an answer b. The null and alternative hypotheses would be: Ho: ?v Select an answerv H: ?vSelect an answerv C. The test statistic ?v = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ?v a f. Based on this, we should Select an answerv the null hypothesis. R. Thus, the final conclusion is that 2

Two friends, Karen and Jodi, work different shifts for the same ambulance service. They wonder if the different shifts average different numbers of calls. Looking at past records, Karen determines from a random sample of 40 shifts that she had a mean of 5.1 calls per shift. She knows that the population standard deviation for her shift is 1.2 calls. Jodi calculates from a random sample of 31 shifts that her mean was 5.8 calls per shift. She knows that the population standard deviation for her shift is 1.4 calls. Test the claim that there is a difference between the mean numbers of calls for the two shifts at the 0.01 level of significance. Let Karen's shifts be Population 1 and let Jodi's shifts be Population 2.   Step 3 of 3 :   Draw a conclusion and interpret the decision.