Given a normally distributed random variable X with a µ=5.3 and σ=2.1, find 90th percentile.Question 2Answera.8.89b.7.07c.7.99d.4.32

To find the 90th percentile of a normally distributed random variable, we need to find the z-score that corresponds to the 90th percentile.

The z-score for the 90th percentile can be found in a standard normal distribution table or calculated using a calculator or software that can handle statistical functions. The z-score for the 90th percentile is approximately 1.28.

The formula to convert a z-score to an x-value in a normal distribution is X = µ + Zσ.

Substituting the given values:

X = 5.3 + 1.28(2.1) = 5.3 + 2.688 = 7.988

So, the 90th percentile of this distribution is approximately 7.99. Therefore, the correct answer is c. 7.99.