given that X is a normal variable, which of the following statements is/are true: a. the variable X+3 is also normally distributed b. the variable X-2 is also normally distributed c. the variable 5X is also naormally distribued d. all of the above are true e none of the above are true

(a) Explain briefly and in nontechnical language what “a significant difference (P < 0.01)” means. (b) Explain clearly and briefly what “95% confidence” means. (c) Is this study good evidence that requiring job training of all welfare mothers would greatly reduce the percent who remain on welfare for several years?

Reflect on the “Managing Ashland MultiComm Services” case information presented throughout the assigned questions in Part 1. Write an explanation of how you would respond to the following scenario: You have been asked by J. Doe, the leader of the technical operations department, to only test to see if there is a difference between the mean target and the actual results. Some employees in the department have mentioned that J. Doe is seeking approval for new equipment that will increase speed. Prior requests have been declined and the leader wants to use your results to prove new equipment is required. […]

A college teacher wishes to estimate the mean number of hours worked per week at​ non-college related jobs by​ full-time students at the college. He desires a margin of error of 1.5 hours. Past studies suggest that a population standard deviation of 14.5 hours is reasonable. Estimate the minimum sample size needed to estimate the population mean with the stated accuracy.

For the given​ event, state whether the difference between what occurred and what you would have expected by chance is statistically significant or not statistically significant. In 36 rolls of two​ six-sided dice, the numbers on the dice add to 2 ten times.