Question

Styles Pane J Ways Review View Acrobat A A A A E 211 Aadbccbdte Aalbcode AaBbCcDc AaBbccdd6 AaBb, BADAE Normal No Spacing Heading 1 Heading The 2. Denis Kearns Donuts operates a chain of coffee/donut shops across Canada. Recently, out of concern for public health, they have blocked off their seating area. They would like to know what this has done to the average spending by customers. 16 customers are sampled and the sample has a mean spending of $12 per customer with a standard deviation of $4. a. What assumption do we need to make about the shape of the distribution of customer spending? Why? b. Kearns would like to conduct a larger study to reduce the margin of error to no more than $1.50 at the 95% confidence level. How many people should they sample? 3. The Thrifty Market would like to know if people buying habits have changed due to the public health emergency. They asked 100 people if they have decreased the amount of time they shop. 65 responded yes. a. Give the 95% interval estimate for the true proportion of people who spend less time shopping. b. The Thrifty Market would also like to know the proportion of customers who specifically come to the store to purchase toilet paper. If they need the margin of error to be no more than 3% how large a sample should they choose?

Answer 1

☺ na 100 / X=657 a) û Point estimate : A = * = 65 30.65 (6) Margin error: 1 Too Share 2x B cid = r.pe x po-ascuro 6 65 (-0.65 loo V n = 0.093 93.). Confidence Interval ü) CI n 0.65 6S -0 low a 10.557,0.743) 9f Mongin error = 0.03 P = 0.65 ne ze x 0.6511-0.65) = 1.9612065x(1-01681 (6.03)2 10.032 = 3.84168 0.2275 ~ 971 0.0009