20. Company records show that drivers get an average of 32,500 miles on a set of Road Hugger radial tires. Hoping to improve the average mileage, the company has added a new polymer to the rubber that should help protect the tires from deterioration. The hypotheses Ho : u = 32,500 and H1 : u> 32,500 are to be tested using a significance level a=0.05, where u is the average mileage on the new tires. (a) A random sample of 25 new tires shows an average of 33,800 miles with a standard deviation of 4,000 miles. Can the company conclude that the new polymer has significantly increased the average mileage of the tires? (You have to write down the decision rule, the test statistic and the conclusion). Solution: For a=0.05, reject H, if t > 1.711, accept Ho ift< 1.711 where t has 24 degrees of freedom. Orf- X 4000//25 33800 – 32500 Test statistic is t = = 1.625 which is less than 1.711. Accept Ho and conclude that sample evidence does not support that new polymer has significantly increased the average mileage of the tires. That is, the company cannot conclude that the new polymer has significantly increased the average mileage of the tires.

How many days are in 9 weeks? Use the following information to convert this time to days. 1week=7 days

18 years from now, Linda will be 4 times older than she is today. How old is Linda today? Answer in numeric format only.

Is 4160 0012 3456 7892 a valid VISA credit card number?  Explain why or why not and support your answer mathematically.  If the number is not, in a complete sentence, explain what change(s) you would make to the number to create a valid identification number.

What I have as an answer is 9.91155 but is wrong. Can you help me thank you.

for number 7 I got 0.00002

Can you redo them without using abbreviations?

Please help me answer the following questions. Thank you

What is the decimal value of 25?