1. The National Assessment of Educational Progress (NAEP) gave a test of basic arithmetic and the ability to apply it in everyday life to a sample of 840 men 21 to 25 years of age. Scores range from 0 to 500; for example, someone with a score of 325 can determine the price of a meal from a menu. The mean score for these 840 young men was x = 272. We want to estimate the mean score ? in the population of all young men. Consider the NAEP sample as an SRS from a Normal population with standard deviation ? = 60. If we take many samples, the sample mean x varies from sample to sample according to a Normal distribution with mean equal to the unknown mean score ? in the population. What is the standard deviation of this sampling distribution?
2. The National Assessment of Educational Progress (NAEP) gave a test of basic arithmetic and the ability to apply it in everyday life to a sample of 840 men 21 to 25 years of age. Scores range from 0 to 500; for example, someone with a score of 325 can determine the price of a meal from a menu. The mean score for these 840 young men was x = 272. We want to estimate the mean score ? in the population of all young men. Consider the NAEP sample as an SRS from a Normal population with standard deviation ? = 60.
According to the 95 part of the 68-95-99.7 rule, 95% of all values of barx with a sample size of 840 fall within on either side of the unknown mean ?. What is the missing number?
3. The National Assessment of Educational Progress (NAEP) gave a test of basic arithmetic and the ability to apply it in everyday life to a sample of 840 men 21 to 25 years of age. Scores range from 0 to 500; for example, someone with a score of 325 can determine the price of a meal from a menu. The mean score for these 840 young men was x = 272. We want to estimate the mean score ? in the population of all young men. Consider the NAEP sample as an SRS from a Normal population with standard deviation ? = 60.
What is the 95% confidence interval for the population mean score ? based on this one sample?
A. 266 to 278
B. 152 to 392
C. 270 to 274
D. 268 to 276
4. What is the critical value z* for confidence level C = 95%?
A. z* = 0.838
B. z* = 2.24
C. z* = 2.32
D. z* = 1.96