Question

Q1: The marks of final exam on a calculus exam are normally dis with a sample standard deviation of 0.51. A random sample of 12 scores on the exam has a mean of 2.71. Find a 90% confidence interval for the mean of the exam grades. 20.05 = 1.64 and 10.05 = 1.80 02: Thirty-five percent of customers had orders exceeding $100. If 20% of the customers have orders exceeding $100 and also pay with credit card, determine the probability that a customer whose order exceeds $100 will pay with the sponsored credit card.

Answer 1

My dear student according to HomeworkLib policy i have solved the one first question thanku.

1.80 x 0.51 n = 18, 5=0.5), X=2.71, C = 90°). Critical valul fa h-) 19-) of=1-0.90=0.1 4/2=0.05 tor/a, df = to 05,11 = 21.80 (using t table] margin of error, E = tape, of x = 512 = 0.265004 90 % Confidence interval E B F E = 2.71 +0.265004 = 8.444996, 2975004 90.8. c.I 2:44.5 eu el <12.975 1<E