Suppose that x is a random variable with mean 20 and standard deviation 5. also
suppose that y is a random variable with mean 40 and standard deviation 10. find the
variance and standard deviation of the random variable z for each of the following
cases. be sure to show your work.
(a) z = 2 + 10x.
(b) z = 10x − 2.
(c) z = x + y.
(d) z = x − y.
(e) z = −3x − 2y.

For a science project, a high school research team conducted a survey of local air temperatures. based on the results of the survey, the found that the average temperatures were around 10 degrees higher than expected. this result was wrong. the trouble with the survey was that most of the locations were exposed to direct sunlight and located over asphalt or sand, which resulted in higher temperatures than normal. this is a classic example of an error in which phase of inferential statistics?

What is the solution for 6 - 7/8? explain the steps.

Suppose your sat score is 2040. a college with an average sat score for admintted students of which of these would most likely be your best option?