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## A random sample of 18 purchases showed the amounts in the table (in $). The mean is $50.91 and the standard deviation is $24.40

A random sample of 18 purchases showed the amounts in the table (in $). The mean is $50.91

and the standard deviation is $24.40.

a) How many degrees of freedom does the t-statistic have?

b) How many degrees of freedom would the t-statistic have if the sample size had been 2

?