# Help with Chebyshev

• May 16th 2009, 10:12 PM
Phil32686
Help with Chebyshev
I agreed to help my cousin with her statistics, but to tell you the truth, I've never taken it. I went straight from Algebra 2 to Calc and then Calc 2 and so forth. Also, I haven't taken a math course in years. So a lot of this stuff I have either forgotten or never seen before. So please help!

The problem says:

A population has a mean of 78 and a standard deviation of 2.8. According to Chebyshev, at least what proportion of this population will lie between 97.6 and 58.4?

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Also, I had another question. This one said P(A and B-) is 0.6. B- stands for B with a line over it. What does B with a line over it stand for?
Full Problem says:

P(A) is 0.8 and P(A and B-) is 0.6. What is P(A and B)? (Hint-try a Venn diagram)
• May 17th 2009, 12:59 AM
CaptainBlack
Quote:

Originally Posted by Phil32686

The problem says:

A population has a mean of 78 and a standard deviation of 2.8. According to Chebyshev, at least what proportion of this population will lie between 97.6 and 58.4?

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You can spell Chebyshev, so you can google "Chebyshev inequality probability"

Quote:

Also, I had another question. This one said P(A and B-) is 0.6. B- stands for B with a line over it. What does B with a line over it stand for?
Full Problem says:

P(A) is 0.8 and P(A and B-) is 0.6. What is P(A and B)? (Hint-try a Venn diagram)
$\displaystyle \overline{B}$ stands for the complement of $\displaystyle B$.

So $\displaystyle P(A\ \text{and}\ \overline{B})$ is the probability that the event $\displaystyle A$ occurs and event $\displaystyle B$ does not occur (as the hint says draw a Venn diagram)

CB
• May 17th 2009, 02:40 AM
Phil32686
Thanks CaptainBlack

I got 97.96% for the chebyshev question

And 0.2 for the P(A and B) question.
• May 17th 2009, 02:52 AM
CaptainBlack
Quote:

Originally Posted by Phil32686
Thanks CaptainBlack

I got 97.96% for the chebyshev question

And 0.2 for the P(A and B) question.

They look OK

CB