Answer:
0.4470 = 44.70% probability of a random person on the street having an IQ score of less than 98.
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
What is the probability of a random person on the street having an IQ score of less than 98?
This is the pvalue of Z when X = 98. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{98 - 100}{15}[/tex]
[tex]Z = -0.1333[/tex]
[tex]Z = -0.1333[/tex] has a pvalue of 0.4470
0.4470 = 44.70% probability of a random person on the street having an IQ score of less than 98.