Question

Please help with 5,6,7, please show your work as well!

10 out of 10 points Question 1 A population has a mean of 60 and a standard deviation of 30. Samples of size 16 are randomly selected. Calculate the standard deviation of the sample distribution of X. Round off to 3 decimal places. 15 out of 15 points Question 2 Samples of size 16 are drawn from a population. The sampling distribution for X has a standard deviation of 0.25. Find the standard deviation of the population. Round off to three decimal places. O out of 15 points Question 3 A population has a probability distribution as follows. X PO 1 02 20.5 3 0.3 A sample of 2 is drawn and its mean, X, calculated. Find the probability - 2.0 15 out of 15 points Question 4 Tires are found to have a mean life of 40.000 miles. The standard deviation is 8000. A sample of 400 is chosen. Find the probability that 40,500 < x 15 out of 15 points Question 5 Tires are found to have a mean life of 800 hours. The standard deviation is 50. A sample of 100 is chosen. Find the probability that 40 800 < X <812. 15 out of 15 points Question 6 A sample of size 64 is chosen from a population. The sample mean is 50 and the standard deviation is 5. Find the upper limit of the 85% confidence interval for the population mean. Round off to three decimal places. Question 7 O out of 15 points A sample of size 64 is chosen from a population. Assume the probability distribution is normal. If the mean of the sample is 110 and the standard deviation is 6, find the lower bound of the 99% confidence interval. Round off to three x decimal places.

Answer 1

3 и – чоооо 6 - 8 боо n = 400 к (ху чо5оо ) - e(Х-и s > 405oo чоооо 800 - (> 1.25) 6. JOS6 y: ts – goo, Б- So ост до (844 2 818) ) 3 с &\t-оо So 10. ) No5 (o2 Z с 2 .4) = (а с 2.4) - Yo) 099 1% - 0 S 2.4 о. 4918

n=64 X=so, s=5, tool ş =t63, o os 2.00 2 me= tn-l m - 2 x vra 1-25 lower limit = ame =50 -1.25 = 48.75 Upper limit=7+me -30 1.25 -51.25 Upperlimit= 51.250 o X=110, 6=6 n=64 lower bound X-la $ so llo (2.580161 Vog 108.065