Question

The distribution of the amount of money spent by first-time gamblers at a major casino in Las Vegas is approximately normal in shape with a mean of $600 and a standard deviation of $120. According to the standard deviation rule, almost 84% of gamblers spent more than what amount of money at this casino?

A. $360
B. $480
C. $600
D. $720
E. $840

Answer 1

$720

Explanation:

Given :

Mean, m = 600

Standard deviation, s = 120

Z = (x - m) / s

P(Z > x) = 84%

P(Z > x) = 0.84

Zscore corresponding to P(Z > x) = 0.84 will be -0.994

Hence,

-0.994 = (x - 600) / 120

120 * -0.994 = x - 600

119.28 = x - 600

119.28 + 600 = x

719.28 = x

Hence,

X = $720