Introduction

You have learned about a very important class of statistical methods called hypothesis tests. The techniques of hypothesis testing provide a formal way to use sample data to test claims made about population parameters. In this project you will setup and conduct tests where the sample data is collected from Internet based sources. First you must collect and understand the data and its source.　 In some of the exercises you will not be pointed directly at the data as before, rather you will need to use Internet search engines to track down what you need.

Utility Prices

At the Bureau of Labor Statistics site http://www.bls.gov/data/ , locate the average price data for electricity measured per 500 KWH (kilowatt-hour) from 2000 to the present.　 For example the row for 2000 would look like
2000　　 45.207　　 45.542　　 45.598　　 ...　　 46.404

indicating, for instance, that in March of 2000, the cost of 500 kilowatt-hours of electricity cost $45.598 .
In the exercises you will be studying the variation within a year as well as across years.

Intelligence and the IQ Test

A person's IQ (Intelligence Quotient) was initially defined as follows
.
Thus an IQ of 100 implies one's mental age is in agreement with one's actual age in years so such a person is very normal and of average intelligence. A 10-year-old with an IQ of 130 has the intelligence level of a typical 13-year-old.
Over the years, researchers in education and psychology have debated the issues associated with the accurate determination and interpretation of a person’s IQ. One of the earliest accepted standards was the Stanford-Binet IQ test which arose from work by the French psychologist Alfred Binet later modified by psychologists at Stanford University. In the mid-twentieth century, the Wechsler Adult Intelligence Scale (WAIS) developed by David Wechsler, was introduced and is favored today.
At the Data and Story Library site ( http://lib.stat.cmu.edu/DASL/ ) you will find a summary of an experiment designed to study the correlation (if any) between brain size and IQ. We are not interested in the correlation experiment itself but the associated data file provides a set of Wechsler IQ scores that you will work with in the exercises. Visit the DASL site, locate the data file for this experiment, and be sure you understand the meaning of the individual data points continuing to the exercises.
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Exercises

When you've finished reviewing this project, go on to the exercises below.

1. 
   Test the hypothesis that the standard deviation of the price of 500 KWH of electricity is $1.25. Use a 0.05 level of significance. Use the 2000 data.
   
2. In each year of data, which month exhibits the highest price per 500 KWH? Can you think of reasons why?
3. 
   Wechsler IQ scores typically follow a distribution with mean 100 and standard deviation 15. Using the Full Scale IQ scores for all the test subjects, first test the hypothesis that the standard deviation in IQ is 15 points.　 Based on the outcome of that test, conduct the appropriate tests of the claim that the mean is 100 points. Use a 0.05 level of significance.
   
   
4. The mean of the twenty male IQ scores is 115. Test the hypothesis that the mean of female IQ scores is less than 115. Note: This test is not comparing the mean IQ of females to that of males, it is simply using 115 as a comparison value. In the next chapter you will learn how to compare the means of two populations. Use a 0.05 level of significance.
   
   

Price: $20.59

Solution: The downloadable solution consists of 11 pages, 959 words and 4 charts.
Deliverable: Word Document