Critical values for quick reference during this activity; Condence level Critical value \\.-..-. 40292;;st 35 cpzqv? ' l The manager of a bookstore with a coffee shop wants to know the proportion of customers th the store because of the coffee shop. A random sample of 75 customers was polled. Use Shes [ Excel le linked above to calculate and the 95% confidence interval. 15 = Ex:1.234 Upper bound for 95% confidence intenral = Ex: 1.234 Lower bound for 95% confidence interval = The manager can say with 95% confidence that the true population proportion of the custom come into the store because of the coffee shop is in the interval [ Ex: 1234 , ]