Question

money in 81 accounts in a bank had a mean of $1200 and a std of $146. test the hypothesisto see if population mean is equal to $1160. test at a =0.05

Answer 1

given data are:-

sample size (n) = 81

sample mean () = 1200

sample sd (s) = 146

here. we will do 1 sample t test for mean ,as the sample sd is known.

hypothesis:-

test statistic:-

df = (n-1) = (81-1)= 80

p value = 0.0158

[ in any blank cell of excel type =T.DIST.2T(2.466,80) press enter]

decision:-

p value = 0.0158 <0.05(alpha)

so, we reject the null hypothesis.

conclusion:-

there is not sufficient evidence to support the claim that the population mean is equal to $1160 at 0.05 level of significance.

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