Answer:
82.64
Step-by-step explanation:
Mean = 80 ; σ² = 36 ; σ = √36 = 6
Using the relation :
P(Z < x) = (x - mean) / standard deviation
P(Z < x) = 0.67
Z = invNorm(0.67) = 0.44
Hence,
0.44 = (x - 80) / 6
Cross multiply :
6 * 0.44 = x - 80
2.64 = x - 80
2.64 + 80 = x
82.64 = x
Hence, X = 82.64
