Young people have a better chance of full-time employment and good wages if they are good with numbers. How strong are the quantitative skills of young Americans of working age? One source of data is the National Assessment of Educational Progress Young Adult Literacy Assessment Survey, which is based on a nationwide probability sample of households. The NAEP survey includes a short test of quantitative skills covering mainly basic arithmetic and the ability to apply it to realistic problems. Scores on the test range from 0 to 500. For example, a person who scores 233 can add the amounts of two checks appearing on a bank deposit slip, someone scoring 325 can also determine the price of a meal from a menu, a person scoring 375 can transform a price in cents per ounce into dollars per pound. Suppose that you give the NAEP test to an SRS of 840 people from a large population in which the sores have mean 280 and standard deviation of 60. The mean of the 840 scores will vary if you take repeated samples.

Describe the shape, center, and spread of the sampling distribution of sample means.

According to the 68-95-99.7 Rule, about 95% of all the values of fall within ___ deviations of the mean of this curve. What is the missing number? Call it m for the "margin of error"

In what percent of all samples will the true mean = 280 be covered by the confidence interval, ?