A person must score in the upper of the population on an IQ test to qualify for membership in Mensa, the international high-IQ society. If IQ scores are normally distributed with a mean of and a standard deviation of , what score must a person have to qualify for Mensa (to whole number)

The person must score at least , in which Z has a p-value of , considering p the upper percentage the person must score, is the mean IQ score for the population and is the standard deviation.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean and standard deviation , the z-score of a measure X is given by:

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.

In this question:

Mean , standard deviation

What score must a person have to qualify for Mensa?

Score of at least X, given by:

In which Z has a p-value of , considering p the upper percentage the person must score.

5.  2898.59.

7. 42%