Critical values for quick reference during this activity.

Confidence level	Critical value
0.90	z=1.645
0.95	z=1.960
0.99	z=2.576

377158.2334820.qx3zqy7

Start

The manager of a bookstore with a coffee shop wants to know the proportion of customers that come into the store because of the coffee shop. A random sample of 75 customers was polled. Use Sheet 3 of the Excel file linked above to calculate p^ and the 95% confidence interval.

p^=

Upper bound for 95% confidence interval =

Lower bound for 95% confidence interval =

The manager can say with 95% confidence that the true population proportion of the customers that come into the store because of the coffee shop is in the interval [000000000,000000000].

Spread sheet data 3

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