A random sample of 132 observations produced a sample mean of 29. Find the critical and observed values of z for the following test of hypothesis using a = 0.01. The population standard deviation is known to be 5 and the population distribution is normal. Ho: H = 28 versus H:u + 28. Round your answers to two decimal places. Zcritical left = Zeritical right = Zobserved =

For men heights are normally distributed with a mean of 69 inches and a standard deviation of 2.8 inches. If samples of 25 men are selected at random from the population, would the average height found for each sample be more or less varied than the individual measurements taken for each man?B

Brewed decaffeinated coffee contains some caffeine. We want to estimațe the amount of caffeine in 8 ounce cups of decaf coffee at local fast food restaurants. For this question, assume that the standard deviation in the amount of caffeine in 8 ounces of decaf coffee is not known and is estimated to be 2.3 mg using the samplestandard deviation. This time we took a sample of n = 9 eight-ounce cups of coffee from fast food restaurants on Robert Street in West St. Paul. The sample mean amount of caffeine turned out to be 9 mg. Construct a 99% confidence interval estimate for the true mean amount of caffeine in eight-ounce cups of decaf coffee, using the new information described above. Type the formula for your confidence interval into the text box first and then type a second version where you fill in all of the numbers in your formula. You don't have to calculate the final numeric result.

The average monthly, entry-level salary for fresh graduates was reported as $2,800. A recruiting agency believed that the mean salary of fresh entry is lower than this. The recruiting office randomly surveyed 25 entry-level graduates and found that the sample means salary is $2,200, and the sample standard deviation is $1800. Assuming t- distribution is followed, answer the following questions. Use: H0 : u>2800 H1 : u

You take random sample of 200 people from Salinas and find that their average income is $48, 000 per ssalazar@stuce X year with a standard deviation of $9000. Also assume that population incomes are normally Email om sampile of 200 distributed. om sangle cf 200 X Approximately how many people make between $39,000 and $57,000? Uplead on sanple cf 200 X 200 O Cirf-I Answer format: Enter a positive integer Text

A coffee vending machine is adjusted so thatthe quantity of beverage poured is a normal variable ofaverage 200 ml. You buy 15 cups of coffee and you noticethat the average volume is 195 ml with a standard deviationof 2.3 ml. Can you file a complaint against the ownerof this machine for the lack of coffee in your glasses?Test at the 5% level.

In a random sample of 6 cell phones, the mean full retail price was $547.30 and the standard deviation was $176.00. Further research suggests that the population mean is $428.25. Does the t-value for the original sample fall between and to.95? Assume that the population of full retail prices for cell phones is normally distributed. - to.95 The t-value of t = fall between -1 -to.95 and to. .95 because to 95 = (Round to two decimal places as needed.)

State the conclusion based on the results of the test. The standard deviation in the pressure required to open a certain valve is known to be o = 0.8 psi. Due to changes in the manufacturing process, the quality-control manager feels that the pressure variability has increased. The null hypothesis was rejected. Choose the correct answer below. O A. There is sufficient evidence that the standard deviation in the pressure required to open a certain valve has increased. O B. There is not sufficient evidence that the standard deviation in the pressure required to open a certain valve has not changed. OC. The standard deviation in the pressure has not changed. O D. There is sufficient evidence that the standard deviation in the pressure required to open a certain valve has not changed. O E. The standard deviation in the pressure has increased. O F. There is not sufficient evidence that the standard deviation in the pressure required to open a certain valve has increased.

See pictures for question D and E and (A, B and Cand was submitted on a different question. According to a report done by S & J Power, the mean lifetime of the light bulbs it manufactures is 44 months. A researcher for a consumer advocate group tests this by selecting 16 bulbs at random. For the bulbs in the sample, the mean lifetime is 47 months. It is known that the population standard deviation of the lifetimes is 5 months. Assume that the population is normally distributed. Can we conclude, at the 0.10 level of significance, that the population mean lifetime, μ, of light bulbs made by this manufacturer differs from 44 months? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places, and round your responses as specified below.

If someone could help me answer this that would be great.