QUESTION 1

(S-AQ 11.45) To estimate the mean height u of male students on your campus, you wi||_measure an SRS of students. You know from government data that the standard deviation of the heights of young men is about 2.4 inches. You want your sample mean x to estimate u with an error of no more than one-half inch in either direction. What standard deviation (0.0001) must I have so that 99.7% of all samples give an 7r within one-half inch of 1.1? (Use the 68-95-99] rule) D How large an SRS do you need to reduce the standard deviation of}? to the value you found in the previous part? C] (19.04) During World War 11, 12,000 able-bodied male undergraduates at the University of Illinois participated in required physical training. Each student ran a timed mile. Their times follow_ed the Normal distribution with mean 7.11 minutes and standard deviation 0.74 minute. An SRS of 100 of these students has_mean time x = 7.15 minutes. A second SRS of size 100 has mean x = 6.97 minutes. _ After many SRSs, the many values of the sample mean x follow the Normal distribution with mean 7.11 minutes and standard deviation 0.074 minute. Step 1: What is the population? 0 The population is an SRS of size 100 taken from the 12,000 students. 0 The population is all able-bodied males in the U.S. O The population is the 12,000 able-bodied male undergraduate at the University of Illinois. 0 The population is all SRSs of size 100 taken from the 12,000 students. Step 2: What values does the population distribution describe? 0 The two distributions are the same. 0 The population distribution describes the average mile-time for 100 randomly selected students. 0 The population distribution describes the time it takes a randomly selected individual to run a mile. Step 3: What is this distribution? 0 Normal with mean 7.11 minutes and standard deviation 0.74 minute. 0 Normal with mean 0.711 minutes and standard deviation 0.074 minute. 0 Can't answer from these data. 0 Normal with mean 0.0711 minutes and standard deviation 0.74 minute. 0 Normal with mean 7.11 minutes and standard deviation 0.074 minute. Step 4: _ What values does the sampling distribution of x describes? O The sampling distribution of; describes the time it takes a randomly selected individual to run a mile. 0 The sampling distribution of; describes the average mile-time for 100 randomly selected students. 0 The sampling distribution of; describes the average mile-time for increasing number of randomly selected students. 0 All the above distributions are the same