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. Click to view page 1 of the table. LOADING... Click to view page 2 of the table. LOADING...

xx 0.750.75 A graph with a bell-shaped curve, divided into 2 regions by a line from top to bottom, on the right side. The region left of the line is shaded and labeled 0.75. The x-axis below the line is labeled "x".

The indicated IQ​ score, x, is

Answer 1

Solution:-

Given that,

mean = = 100

standard deviation = = 15

Using standard normal table,

P(Z < z) = 0.75

= P(Z < 0.67 ) = 0.75  

z = 0.67

Using z-score formula,

x = z * +

x = 0.67 * 15 + 100

x = 110.1