Question

Maureen McIlvoy, owner and CEO of a mail order business for wind surfing equipment and supplies, is reviewing the order filling operations at her warehouses. Her goal is 100% of orders shipped within 24 hours. In previous years, neither warehouse has achieved the goal, but the East Coast Warehouse has consistently out-performed the West Coast Warehouse. Her staff randomly selected 200 orders from the West Coast Warehouse (population 1) and 400 orders from the East Coast Warehouse (population 2), and reports that 190 of the West Coast Orders were shipped within 24 hours, and the East Coast Warehouse shipped 356 orders within 24 hours. Assuming α = 0.05, the observed z value is ___________________.

		-3.15
		2.42
		1.53
		0.95
		1.05

Answer 1

The following information is provided: (a) Sample 1 - The sample size is N1 = 200, the number of favorable cases is X1 = 190 and the sample proportion is p^1​=X1/N1​=190/200​=0.95 (b) Sample 2 - The sample size is N2 = 400, the number of favorable cases is X2 = 356 and the sample proportion is p^2​=X2/N2​=356/400​=0.89 and the significance level is α=0.05 Pooled Proportion: The value of the pooled proportion is computed as Test Statistics The z-statistic is computed as follows: