Georgina likes to read during her summer break. The table below shows the number of pages in each book she read last summer and the number of pages in each book she read this summer.

Number of Pages Georgina Reads during the Summer

Last Summer

140

220

190

180

190

This Summer

150

170

150

190

180

What inference can someone draw about the data?
The books she read this summer had more pages, on average, than last summer.
The number of pages in each book varied more last summer than this summer.
Last summer, the average book had nearly twice the number of pages than the average book has this summer.
This summer, the number of pages in a book varied nearly twice as much as the number of pages in last summer's books

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.