Question

Without using a normal curve table, about what Z score would a person have who is at the start of the top (a) 50% (b) 16% (c) 84% (d) 2%?

a) (a) 1, (b) 2, (c) -1, (d) -2
b) (a) 0, (b) 1, (c) -2, (d) -3
c) (a) -1, (b) -2, (c) 1, (d) 2
d) (a) 2, (b) 1, (c) -2, (d) -1

Answer 1

The z-scores for different percentiles follow a pattern called the empirical rule.

Step-by-step explanation:

The z-scores for +20 and -20 are +2 and -2, respectively.

The z-scores for +30 and -30 are +3 and -3, respectively.

So, in other words, this is that about 68 percent of the values lie between z-scores of -1 and 1, about 95% of the values lie between z-scores of −2 and 2, and about 99.7 percent of the values lie between z-scores of -3 and 3.

The empirical rule is also known as the 68-95-99.7 rule.