A study comparing weekly expenditures per-person on groceries by people in two different neighborhoods draws a sample of size 40 from each neighborhood. From previous work, the population standard deviations are known to be $24 for the rst neighborhood and $18 for the second. For the rst sample, the mean is $40 and the standard deviation is $20. For the second sample, the mean is $36 and the standard deviation is $18. What is the 98% condence interval for the difference in means? "1.615;\" #2 56.38 \" 1.61 gm #2 54.38 4.615;\" M 56.38 2.61 gm M s 6.38