1. ## Normal distr

Problem 5.21 Newbold
See image

My attempt:
1. See image2

2. Searching for it in this table Public Domain Normal Distribution Table
I find z=0.06

3. Thus, a=0.06

Correct?

2. ## Re: Normal distr

a) The z-score for 0.4 is $\displaystyle z=\frac{0.4-0.2}{0.05}=4$, but your table only goes up to $\displaystyle z=3.09$ so we would use the approximation:

$\displaystyle P(X>4)=0$

3. ## Re: Normal distr

Using numeric integration, I find:

$\displaystyle P(X>4)\approx0.00003167124184$

4. ## Re: Normal distr

Sorry, I didn't say that I was trying to do e. (But yes, in a. P ≈ 0).