Читать книгу Student Study Guide to Accompany Statistics Alive! - Wendy J. Steinberg - Страница 32

1 The average amount of time people spend on a certain mobile application is 4.5 min/day, and the standard deviation is 0.75. What is the variance of the minutes spent per day on this application?

2 Why do we use n – 1 in the denominator of the variance formula when estimating a population variance from a sample?

3 In general, how would adding outliers to a distribution affect the dispersion?

4 What are descriptive statistics? Give examples of this type of statistic.

5 What are inferential statistics? Why are they important in our study of statistics?