Question

Use the normal table, and for all the problems a normal curve drawing is a must pleaseeeee

1. P(-2.1<z<0)

2. P(1.3<z<1.9)

3. P(-2.1<z<1.1)

4. P(-b<z<b)=.92

5. P(z>.13)

Answer 1

1;

Following is the curve:

2:

Following is the curve

3;

Following is the curve

4:

Here we need z-scores that have 0.92 area between them. That is we need z-scores that have (1-0.92)/2 = 0.04 area at both tails.

From z table, the z-score -1.75 has 0.04 z-score to its left. By symmetry z-score 1.75 has 0.04 area to its right. So

Answer: b =1.75

Following is the curve:

5:

Following is the curve: