Question

Independent random samples of weekend and weekday shoppers were selected and amount spent per trip to the mall was recorded as shown in the following table. Obtain 95% confidence interval for the difference of the mean amount spent. Is there sufficient evidence to claim that there is a difference in the mean amount spent per trip on weekend and weekday? Assume normality, equal variances, α = 0.05. (z0.025 = 1.96, t0.025,47 = −2.0117, t0.025,45 = −2.0141)

Sample size (n) weekends 25 weekdays 22

Average (X) weekends $85 weekdays $55

Just trying to check my work. Thanks

Sample std dev (s) weekends $8 weekdays $7

Answer 1

To calculate the confidence intervel we will use t distribution.