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