Alice wants to compare whether the price on a birthday cake in two supermarkets differs significantly. She wrote down the daily prices for the last few days and found the difference between the sample means to be $4.01. If the standard deviation of the difference between sample means is $5.46, what is the 95% confidence interval of the sample mean difference?

a:between -8.02 and +8.02
b:between -10.92 and +10.92
c:between -12.03 and +12.03
d: between -16.38 and +16.38

Question

Alice wants to compare whether the price on a birthday cake in two supermarkets differs significantly. She wrote down the daily prices for the last few days and found the difference between the sample means to be $4.01. If the standard deviation of the difference between sample means is $5.46, what is the 95% confidence interval of the sample mean difference?

a:between -8.02 and +8.02
b:between -10.92 and +10.92
c:between -12.03 and +12.03
d: between -16.38 and +16.38

anonymous · Answer

please help!!!!