Aquality analyst wants to construct a control chart for determining whether three machines, all producing the same product, are under control with regard to a particular quality variable. accordingly, he sampled four units of output from each machine, with the following results:

machine measurements

#1 17 15 15 17

#2 16 25 18 25

#3 23 24 23 22

for upper and lower control limits of 23.29 and 16.71, which machine(s), if any, appear(s) to have an out-of-control process mean?

a.
machine #1

b.
machine #2

c.
machine #3

d.
all of the machines

e.
none of the machines

Sales at a fast-food restaurant average $6,000 per day. the restaurant decided to introduce an advertising campaign to increase daily sales. to determine the effectiveness of the advertising campaign, a sample of 49 days of sales were taken. they found that the average daily sales were $6,300 per day. from past history, the restaurant knew that its population standard deviation is about $1,000. if the level of significance is 0.01, have sales increased as a result of the advertising campaign? multiple choicea)fail to reject the null hypothesis.b)reject the null hypothesis and conclude the mean is higher than $6,000 per day.c)reject the null hypothesis and conclude the mean is lower than $6,000 per day.d)reject the null hypothesis and conclude that the mean is equal to $6,000 per day.expert answer