Purchase Solution

Analyse distribution of IQ scores in Americans

Not what you're looking for?

Ask Custom Question

From a population of 25,000 Americans in 1969; it was discovered that their collective IQ Score mean was 105 with a standard deviation of 12.

a. how many IQ scores exceeded 115?

b. what is the probability of IQ scores that fell between 68 and 75?

c. how many IQ scores fell above 3 standard deviations?

d. what is the percentage of IQ scores less than 125?

e. find where the worst 70% of IQ scores fall?

f. to be considered a "genius"; an IQ score must exceed 145; how many made it?

g. find a 90% confidence interval?

h. how many IQ scores fall below 1 standard deviation?

i. find where the worst 10% of IQ socres will fall?

j. find the best IQ score?

Purchase this Solution

Solution Summary

The expert analyzes the distribution of IQ scores in Americans. The percentages of IQ scores less than 125 are determined.

Solution Preview

There are many ways in which you can calculate using the computer. If you want to use excel, there is a very good tutorial on http://www.dacc.edu/~dyork/normal_distribution.htm. It tells you how to input the parameters.

If you are not asked to use excel explicitly, I suggest that you use this online calculator, much easier than excel. ...

Purchase this Solution


Free BrainMass Quizzes
Income Streams

In our ever changing world, developing secondary income streams is becoming more important. This quiz provides a brief overview of income sources.

Managing the Older Worker

This quiz will let you know some of the basics of dealing with older workers. This is increasingly important for managers and human resource workers as many countries are facing an increase in older people in the workforce

Motivation

This tests some key elements of major motivation theories.

MS Word 2010-Tricky Features

These questions are based on features of the previous word versions that were easy to figure out, but now seem more hidden to me.

Production and cost theory

Understanding production and cost phenomena will permit firms to make wise decisions concerning output volume.