Adult IQ scores have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. Use the Empirical Rule to find the percentage of adults with scores between 70 and 130.
Random
stratified
cluster
systematic

Question

Adult IQ scores have a bell-shaped distribution with a mean of 100 and a standard deviation of 15. Use the Empirical Rule to find the percentage of adults with scores between 70 and 130.
	Random
	stratified
	cluster
	systematic

kropot72 · Answer

Do you know the empirical rule regarding standard deviations and percentages?
Note: Your question includes choices that relate to another unrelated question.

kropot72 · Answer

In the bell-shaped distribution about 68.26% of the total area is included within a distance of plus and minus 1 standard deviation from the mean.
About 95.45 of the total area is included within a distance of plus and minus 2 standard deviations from the mean.
In this problem the scores are both 2 standard deviations from the mean:
100 - (2 * 15) = 70 and 100 + (2 * 15) = 130.
Now can you see the answer?

kropot72 · Answer

*About 95.45% is included.........