John has six bills of paper money in the following denominations $1, $5, $10, $20, $50, and $100. If he selects 3 bills at a time what is the probability of selecting a group that has an average value of at least $26?

Answer 1

I would figure the prob of getting 25 or less first.

You cant choose three of those bill to get 25 or less. So the probablility of getting an average of 26 dollars is 1.

Now, if you mean by average value getting a total amount on the three bills of 26*3 or more,

Pr(78dollars)=Pr(100, x x)=1/6
pr(50,20, x)=1/6*1/5
Pr(50,10,10)=1/6*1/5*1/4
I don't see any other way to get a total of 78 dollars or more, so add these three probablilities.

Answer 2

A national caterer determined that 87% of the people who sampled their food said that it was delicious. A random sample of 144 people is obtained from a population of 5000. The 144 people are asked to sample the caterer's food. Will the distribution of , the sample proportion saying that the food is delicious, be approximately normal? Answer Yes or No.

Answer 3

0.55