The management of a supermarket wanted to investigate whether the male customers spend less money on...

The management of a supermarket wanted to investigate whether the male customers spend less money on average than female customers. A sample of 22 male customers who shopped at this supermarket showed that they spent an average of $73 with a standard deviation of $17.50. Another sample of 20 female customers who shopped at the same supermarket showed that they spent an average of $87 with a standard deviation of $14.40. Assume that the amounts spent at this supermarket by all male and female customers are normally distributed with unequal and unknown population standard deviations.

a.) Construct a 90% confidence interval for the difference between the mean amounts spent by all male and all female customers at this supermarket.

b.) Using the 2.5% significance level, can you conclude that the mean amount spent by all male customers at this supermarket is less than that by all female customers?

c) Interpret the conclusion obtained in part b.

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Expert Solution

orchestra answered 11 months ago

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