## anonymous 4 years ago X has a normal distribution. μ=32 Variance=σ2 Given that the probability that X < 33.14 is 0.60406, find the variance to 2 d.p.

1. anonymous

variance = $\sigma^2$

2. anonymous

look up Z-value of 0.60406 Z = (33.14 -32)/s , where s^2 is variance

3. anonymous

Sorry, the probability is 0.6406

4. anonymous

which is 0.36 for z value

5. anonymous

i meant you need the Z-value that corresponds to the probability of .6406 ok

6. anonymous

0.36 = 1.14/s --> s = 1.14/0.36 then square it to get variance

7. anonymous

dumb cow how did u get that dp? did they give it to you?

8. anonymous

display picture

9. anonymous

Ah Ok. Why did you have to square it?

10. anonymous

oh that...its the default icon that i just saved to paint and messed around with it

11. anonymous

because variance = standard deviation ^2

12. anonymous

Ah Ok. Thanks! :)

13. anonymous

root variance=s.d