Question

x = 70 and z = -0.28. use the z - table and describe 70 as a percentile rank. -28% 39% 34% -29% 31%

Explanation:

Step1: Understand z - table usage

The z - table gives the cumulative probability $P(Z\leq z)$ for a standard normal random variable $Z$.

Step2: Look up the value in z - table

Looking up $z=- 0.28$ in the standard normal (z -) table, we find that $P(Z\leq - 0.28)=0.3897\approx39\%$. The percentile rank of a value $x$ (corresponding to $z = - 0.28$ here) is the percentage of values in the distribution that are less than or equal to $x$.

Answer:

B. 39%