Answer:
The probability of a rating that is between 170 and 220 is 0.3811
Explanation:
According to the given data we have the following:
μ=200
σ=50
To calculate the probability of a rating that is between 170 and 220 we would have to use the following formula:
z=x-μ/σ
Therefore, 170-200/50=-0.60
220-200/50=0.40
Using normal cdf formula we get normal cdf(-0.60,0.40)
=0.3811
Therefore, the probability of a rating that is between 170 and 220 is 0.3811