A new Study provides some evidence that playing action video games strengths a person's ability to translate sensory information into accurate decisions. Researchers had 23 male volunteers with an average age of 20 look at moving arrays on computer screens and indicate the direction in which the dots were moving. Half of the volunteers (11 men) reported playing action video game at least five times a week the previous year, while the other 12 reported no video game playing in the previous year. The response time and the accuracy score were both measured. A 95% confidence interval for mean response time for game players minus the mean response time for non-players is -1.8 to -1.2 seconds, while 95% confidence interval for mean accuracy score for game players minus mean accuracy score for non-players is -4.2 to +5.8.

a. Interpret the meaning of the 95% confidence interval for difference in mean response time.

b. Is it likely that game players and non-game players are basically the same in response time? Why or why not? If not which group is faster (with smaller response time)?

c. Interpret the meaning of the 95% confidence interval for difference in mean accuracy score.

d. Is it likely that game players and non-game players are basically the same in accuracy? Why or why not? If not, which group is more accurate?

2. The corner Convenience store kept track of the number of paying customers it had during the noon hour each day for 100 days. The resulting statistics are rounded to the nearest integer:

mean = 95                               midrange = 93

median = 97                            range = 56

mode = 98                               standard deviation = 12

first quartile = 85                     third quartile = 107     

a. The store served what number of paying customers during the noon hour more often than other number? Explain how you determined your answer.

b. On how many days were there between 85 and 107 paying customers during the noon hour? Explain how you determined your answer.

c. What was the greatest number of paying customers during noon hours? Explain how you determined your answer.

d. For how many of the 100 days was the number of paying customers within 3 standard deviations of the mean? Explain how you determined your answer.