Given:
μ = 47, population mean
σ = 3.2, population standard deviation
When the random variable is x = 42, the -score is
z = (42 - 47)/3.2 = -1.5625
From normal tables, the area to the left of is
0.0591 = 5.91%
When x = 50,
z = (50 - 47)/3.2 = 0.9375
The area to the left of z is
0.8257 = 82.57%
Therefore the area between x= 42 and x=50 is
82.57 - 5.91 = 76.66%
Answer: 3)
The correct answer is 76.7%
