Homework Help: Calculus Check

Posted by Matt on Thursday, October 25, 2007 at 8:46pm.

A survey of one thousand people found that 70% of the people have a
CD player, 85% have a telephone, and 45.2% have a computer. At
least how many people have all three objects?

Is the answer 258, because thats what I keep getting?

Calculus Check - drwls, Friday, October 26, 2007 at 12:01am
452 have a computer. That number could include at most 150 with no telephone, but probably fewer. So at least 302 have both computer and phone. The 300 with no CD player could be among that 302, but there are probably fewer. So at least 2 have all three. The most likely number having all three, if the distributions are uncorrelated, is 1000 x 0.452 x 0.7 x 0.85 = 269, but that is not what they ask for.

Answer this Question

Related Questions

Calculus Check - A survey of one thousand people found that 70% of the people ...
Calculus - A survey of one thousand people found that 70% of the people have a ...
Calculus Help? - I have no idea where to start? A survey of one thousand people ...
Cacluluc CHECK - A survey of one thousand people found that 70% of the people ...
Survey ? - Why should people be informed about teen suicide? ( I need like a ...
calculus - A company is taking a survey to find out whether people like its ...
math - you plan to survey people to see what percent own their home and what ...
algebra - 55% of the people in a town have brown eyes. you choose a random ...
Math - In a survey, three out of seven people named blue as their favorite color...
Statistics and Probability - A survey shows that 25% of people listen to the ...

For Further Reading

First Name:
School Subject:
Answer: