Х According to a Nielsen survey, radio reaches 88% of children each week. Suppose we took weekly random
samples of n = 125 children from this population and computed the proportion of children in each sample
whom radio reaches.
What will be the shape of the sampling distribution of the proportions of children the radio reaches?

Choose 1

A. Skewed to the left
B. Skewed to the right
C. Approximately normal
D. Uniform

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.