A major car dealership has several stores in a big city. The owner wants to determine if there is a difference in the proportion of SUVs that are sold at stores A and B. The owner gathers the sales records for each store from the past year. A random sample of 55 receipts from store A shows that 30 of the sales were for SUVs. Another random sample of 60 receipts from store B shows that 42 of the sales were for SUVs. Assuming conditions for inference are met, what is the 99% confidence interval for the difference in proportions of sales that are SUVs?

Find the z-table here.

(0.45 minus 0.30) plus-or-minus 1.96 StartRoot StartFraction 0.45 (1 minus 0.45) Over 60 EndFraction + StartFraction 0.30 (1 minus 0.30) Over 55 EndFraction EndRoot
(0.55 minus 0.70) plus-or-minus 1.96 StartRoot StartFraction 0.55 (1 minus 0.55) Over 55 EndFraction + StartFraction 0.70 (1 minus 0.70) Over 60 EndFraction EndRoot
(0.45 minus 0.30) plus-or-minus 2.58 StartRoot StartFraction 0.45 (1 minus 0.45) Over 60 EndFraction + StartFraction 0.30 (1 minus 0.30) Over 55 EndFraction EndRoot
(0.55 minus 0.70) plus-or-minus 2.58 StartRoot StartFraction 0.55 (1 minus 0.55) Over 55 EndFraction + StartFraction 0.70 (1 minus 0.70) Over 60 EndFraction EndRoot