Question

Okay so can anyone give me a clear understanding of this?
See the attachment.

Answer 1

its Stats and the question is about normal distribution.

Answer 2

Crazy question. My goodness.

Answer 3

Are you asking about 3?

If so, you first need a z table.

Answer 4

It's the boxed one, right?
Our first step is to look at the probability they gave us P(x> 5.2) = .9
find a z score that gives P = .9
That tells us how many standard deviations from the mean 5.2 is.

Answer 5

Find how many sigma above the mean gets you to 0.9

Answer 6

Below the mean, actually.

Answer 7

yes.

then we use the info that mean= 2sigma
so you know
5.2= 2s - as
where a is from the z table.

Answer 8

Yeah, the idea is that you get 2 equations and 2 unknowns. One equation comes from your z-score info. The other equation comes from the mean being twice the SD.

Answer 9

You there, Hashsam1? Ask me questions.

Answer 10

and when we standardize X to Z. and plug 5.2-mean/sigma =a

Answer 11

why is a considered negative?

Answer 12

P(Z>a)=.9 ( and a is considered negative)