Answer:
C. 720.
Step-by-step explanation:
We have been given that the mean of a set of credit scores is 690 and standard deviation is 14.
To find the credit score that is within a z-score of 3.3 we will use z-score formula.
\(z=\frac{x-\mu}{\sigma}\), where,
\(z=\text{z-score}\),
\(x=\text{Raw score}\),
\(\mu=\text{Mean}\),
\(\sigma=\text{Standard deviation}\).
Upon substituting our given values in above formula we will get,
\(3.3=\frac{x-690}{14}\)
Let us multiply both sides of our equation by 14.
\(3.3*14=\frac{x-690}{14}*14\)
\(46.2=x-690\)
Let us add 690 to both sides of our equation.
\(46.2+690=x-690+690\)
\(736.2=x\)
Upon looking at our given values we can see that credit score 720 is within a z-score of 3.3, while 750 is above our given z-score, therefore, option C is the correct choice.
