Three national news networks are trying to estimate what percentage of American voters support a particular presidential candidate. To estimate the
population parameter, each of the three networks collects data from a simple
random sample of voters. Here are the numbers of voters in the networks'
random samples:
• Network A: 2250 voters sampled
• Network B: 2800 voters sampled
• Network C: 2500 voters sampled
Which sample is likely to have the least variability?
A. The Network A sample
Ο Ο Ο
B. The Network B sample
O C. The Network C sample

Suppose we have a set of small wooden blocks showing the 26 letters of the english alphabet, one letter per block. (think of scrabble tiles.) our set includes 10 copies of each letter. we place them into a bag and draw out one block at a time. (a) if we line up the letters on a rack as we draw them, how different ways coukl we fill a rack of 5 letters? (b) now suppose we just toss our chosen blocks into a pile, and whenever we draw a letter we already have, we put it back in the bag and draw again. how many different piles of 5 blocks could result? possible? piles will contain at least one repeated letter? (c) if we draw out 5 blocks wit hout looking at them, how many different piles are (d) if we draw out 5 blocks without looking at them, how many of the possible 2. (4) consider the following formula. 12 give two different proofs, one using the factorial formulas and the other combina torial.