# Math Help - [SOLVED] Help in checking my answer

1. ## [SOLVED] Help in checking my answer

The question goes like this:
Show how to use the chi-square distribution to calculate $P(a

My solution:
$P(a<\frac{S^2}{\sigma^2}
= $P(a(n-1)<\frac{(n-1)S^2}{\sigma^2}<(n-1)b)$
= $P(an-a<\chi^2_{n-1}

2. Originally Posted by noob mathematician
The question goes like this:
Show how to use the chi-square distribution to calculate $P(a

My solution:
$P(a<\frac{S^2}{\sigma^2}
= $P(a(n-1)<\frac{(n-1)S^2}{\sigma^2}<(n-1)b)$
= $P(an-a<\chi^2_{n-1}
Looks OK.

3. Originally Posted by noob mathematician
The question goes like this:
Show how to use the chi-square distribution to calculate $P(a

My solution:
$P(a<\frac{S^2}{\sigma^2}
= $P(a(n-1)<\frac{(n-1)S^2}{\sigma^2}<(n-1)b)$
= $P(an-a<\chi^2_{n-1}
You should justify the step from line two to line three.

CB