# Question

(a) What is the mathematical definition of the variance?

(b) Mathematically, how is a sample’s variance related to its standard deviation and vice versa?

(b) Mathematically, how is a sample’s variance related to its standard deviation and vice versa?

## Answer to relevant Questions

(a) What do SX, SX, and aX have in common in terms of what they communicate? (b) How do they differ in terms of their use? Foofy computes z-scores for a set of normally distributed exam scores. She obtains a z-score of -3.96 for 8 out of 20 of the students. What do you conclude? Poindexter may be classified as having a math dysfunction—and not have to take statistics—if he scores below the 25th percentile on a diagnostic test. The ^ of the test is 75 (aX = 10). Approximately what raw score is ...(a) With what type of data is it appropriate to compute the mean and standard deviation? (b) With what type of data is it appropriate to compute z-scores? (a) What is the restriction of range problem? (b) What produces a restricted range? (c) How is it avoided?Post your question

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