In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data:
mean = 63
standard deviation = 6
Step 02:
distribution (bell-shaped):
68-95-99.7 rule:
63 to 75:
63 + σ = 63 + 6 = 69 ===> 34%
63 + 2σ = 63 + 2*6 = 63 + 12 = 75 ===> 34% + 13.5% = 47.5%
The answer is:
47.5%