Q12. The maker of Surya bulbs wants to demonstrate that their bulbs last on an average of at least 100 hours longer than Ortan bulbs. Two independent random samples of 100 bulbs of each kind are selected. The sample average lives for Surya bulbs found to be 1550 hours and for Ortan bulbs is 2020 hours. Assume that the standard deviation s1 is 75 and the standard deviation s2 is 60 respectively. Find the test Statistic F to test this claim (Round off up to 3 decimal places) a. 1.306 b. 1.562 c. 0.932 d. 0.653

The breaking strengths of cables produced by a certain manufacturer have historically had a mean of 1775 pounds and a standard deviation of 60 pounds. The company believes that, due to an improvement in the manufacturing process, the mean breaking strength, μ, of the cables is now greater than 1775 pounds. To see if this is the case, 90 newly manufactured cables are randomly chosen and tested, and their mean breaking strength is found to be 1788 pounds. Can we support, at the 0.05level of significance, the claim that the population mean breaking strength of the newly-manufactured cables is greater than 1775 pounds? Assume that the population standard deviation has not changed. Perform a one-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below.  a. State the null hypothesis H0 and the alternative hyposthesis H1. b. Find the value of the test statistic. c. Find the p-value. d. Can we…

Assume that weights of adult females are normally distributed with a mean of 79 kg and a standard deviation of 20 kg. What percentage of individual adult females have weights between 73 kg and 85 kg? If samples of 64 adult females are randomly selected and the mean weight is computed for each sample, what percentage of the sample means are between 73 kg and 85 kg? The percentage of individual adult females with weights between 73 kg and 85 kg is 23.6 % (Round to one decimal place as needed.) The percentage of samples of 64 adult females with mean weights between 73 kg and 85 kg is (Round to one decimal place as needed.)

A pizza delivery chain advertises that it will deliver your pizza in 20 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 20minutes. For the simple random sample of 6customers who record the amount of time it takes for each of their pizzas to be delivered, the mean is 21.9 minutes with a standard deviation of 2.1minutes. Assume that the population distribution is approximately normal. Perform a hypothesis test using a 0.025level of significance.   Step 3 of 3 :  Draw a conclusion and interpret the decision.     Answer