How does sleep affect memory? To find out, eight students learned a list of 10 nonsense words one evening. For the next 4 hours, half of them slept and half engaged in activities. Then each tried to recall the list. The next evening everyone learned a new list. Those who had slept did activities and those who were awake the night before slept for 4 hours. Then each recalled the new list. The table shows the number of words each person recalled under the two conditions. Establish a 95% confidence interval about the difference between the two means, findd, and interprate. (Based on a 1924 study by Jenkins and Dallenbach.)