The 70 highest dams in the world have an average height of 206 meters with a standard deviation of 35 meters. the hoover and grand coulee dams have heights of 221 and 168 meters, respectively. the russian dams, the nurek and charvak, have heights with z-scores of + 2.69 and - 1.13, respectively. list the dams in order of ascending size.

Given:

μ = 206 m, the mean

σ = 35 m, the standard deviation.

By definition, the z-score for the random variable, x, is

z = (x - μ) / σ

Therefore,

x = μ + σz

The heights of the given dams are

Hoover:

x = 221 m

Grand Coulee:

x = 168 m

Nurek:

z = 2.69

x = 206 + 35*2.69 = 300.15 m

Hoover:

z = - 1.13

x = 206 - 35*1.13 = 166.45 m

Answer:

In ascending order of x, the dams are

Charvak

Grand Coulee

Hoover

Nurek