Probability: 45% of respondents read Newsweek, 75% read Time

[michaelah169]

1. In a recent survey, 45% of respondents said they were readers of Newsweek Magazine, 75% said they were readers of Time Magazine. 25% said that they read both. What percntage of the respondents:

a)read at least one magazine
b)read neither magazine
c)read Time but not Newsweek
d) If a respondent is selected at random, and it turns out that that person is a reader of Time, how likely is it that that person is also a reader of Newsweek

For part a I have P(N u T) =.45 + .75 - .25 =.95 or 95%. I'm not sure if my work is correct
For part b I have P(N u T)= 1-.95 =.05 again I'm not sure if my work is correct
For part c I created a Venn diagram and got 5%
For part d I got 25%

 

[Loren]

Re: Probability Question

1. In a recent survey, 45% of respondents said they were readers of Newsweek Magazine, 75% said they were readers of Time Magazine. 25% said that they read both. What percntage of the respondents
a)read at least one magazine
b)read neither magazine
c)read Time but not Newsweek
d) If a respondent is selected at random, and it turns out that that person is a reader of Time, how likely is it that that person is also a reader of Newsweek

For part a I have P(N u T) =.45 + .75 - .25 =.95 or 95%. I'm not sure if my work is correct
For part b I have P(N u T)= 1-.95 =.05 again I'm not sure if my work is correct
For part c I created a Venn diagram and got 5% <<<Is this a typo?
For part d I got 25% <<<75% are readers of Time. 25% are readers of Time and Newsweek. If I understand the problem correctly you need to develop a ratio comparing the number of readers of both to the total number of Time readers.

Answers to a and b look good to me.

 

[michaelah169]

Re: Probability Question

It is not a typo, the instuctions said to create a venn digram. I drew it out and made A=.45 and B=.75. In circile A I put .2, in circle B I put .50 and where they overlap I put .25. Thanks for the help.