6. In a normal distribution, what proportion of cases fall between: (a) z 1:00 and z 1:00? (b) z 1:50 and z

6. In a normal distribution, what proportion of cases fall between:

(a) z ¼ 1:00 and z ¼ þ1:00?

(b) z ¼ 1:50 and z ¼ þ1:50?

(c) z ¼ 2:28 and z ¼ 0?

(d) z ¼ 0 and z ¼ þ:50?

(e) z ¼ þ:75 and z ¼ þ1:25?

(f) z ¼ :80 and z ¼ 1:60?