An auditorium has 21 rows of seats. The first row has 18 seats and each succeeding row has 2 more seats than the previous row. How many seats are in the auditorium?

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Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

Arecipe uses 2 cups of sugar to make 32 brownies. how many cups of sugar are needed to make 72 brownies?