1. A random sample of 100 recorded deaths in the United States during the past year showed an average life span of 71.8 years, with a standard deviation of 8.9 years. Does this seem to indicate that the average life span today is greater than 70 years? Use a 0.05 level significance. (Assuming Normal Distribution)
2. The average length of time for students to register for fall classes at a certain college has been 50 minutes. A new registration procedure using modern computing machine is being tried. If a random sample of 12 students had an average registration time of 42 minutes with a standard deviation of 11.9 minutes under the new system, test the hypothesis that the population mean is now less than 50, using a level of significance of 0.05. (Assuming Normal Distribution)
3. A distribution of test scores follows the normal distribution with x? = 80, s = 12, n= 600. How many scores would you expect to find below a score of 90?
4. Above of Z = 1.72

2:29 PM@ 9' 0 ~ .uli ..n-; 62': local_media722939303'i682749526 \\/ Ali/OI\"? 2' The average length of time for students to register for fall classes at a certain college has been 50 minutes. A new registration procedure using modern computing machine is being tried. If a random sample of 12 students had an average registration time of 42 minutes with a standard deviation of 11.9 minutes under the new system, test the hypothesis that the population mean is now less than 50, using a level of signicance of 0.05. (Assuming Normal Distribution} Ha: Ha: oi: Tail: Test Statistic: df: Critical Value/Ta bular Value: Area of Rejection and Acceptance: Computations: Decision: 2.29 PMG (9' a \" III .III' 45-\" -1 l0C8l_media722939303'l682749526 \\/ Air/OI\") l. Steps in Statistical Hypothesis 1. A random sample of 100 recorded deaths in the United States during the past year showed an average life span of 11.8 years, with a standard deviation of 8.9 years. Does this seem to indicate that the average life span today is greater than 70 years? Use a 0.05 level significance. (Assuming Normal Distribution] Ho: Ha: (I! Tail: Test Statistic: df; NONE Critical Value/Tabular Value: Area of Rejection and Acceptance: Computations: Decision: Analysis: 2. The average length of time for students to register for fall classes at a certain college has been 50 minutes. A new registration procedure using modern computing machine is being tried. If a random sample of 12 students had an average registration time of 42 minutes with BIU'AE 2:29 PMCON all all 88 4 local_media7229393031682749526 O E . . . Decision: Analysis: 11. Application of the Normal Curve 3. A distribution of test scores follows the normal distribution with x = 80, s = 12, n= 600. How many scores would you expect to find below a score of 90? a. Solution: b. Area of Z Above of Z = 1.72 a. Solution: b. Area of Z E BIUDA