Question

Find the indicated IQ score. The graph to the right depicts IQ scores of​ adults, and those scores are normally distributed with a mean of 100 and a standard deviation of 15.

xx 0.1431 A symmetric bell-shaped curve is plotted over a horizontal scale. A vertical line runs from the scale to the curve at labeled coordinate x, which is to the right of the curve’s center and peak. The area under the curve to the right of the vertical line is shaded and labeled 0.1431.

The indicated IQ score is

nothing.

​(Round to the nearest whole number as​ needed.)

Answer 1

Area to right of x = 0.1431

Area to left of x = 1 - 0.1431 = 0.8569

Z for area = 0.8569 is 1.07                      (From statistical table of z values)

      = 100 + 1.07 * 15

      = 100 + 16.05

      = 116.05

      = 117                 (Round to nearest whole number)

X = 117