Background: In this week’s discussion, you learned how to construct
probability distributions and graph them. This week, you will review continuous
probabilities, more specifically normal distributions.
You are hired as a statistical analyst for Silver’s Gym, and your boss wants
to examine the relationship between body fat and weight in men who attend the
gym. After compiling the data for weight and body fat of 252 men who attend
Silver’s Gym, you find it relevant to examine the statistical measures and
to perform hypothesis tests and regression analysis to help make general
conclusions for body fat and weight in men.
Part I: Statistical Measures
Statistics is a very powerful topic that is used on a daily basis in many
situations. For example, you may be interested in the age of the men who attend
Silver’s Gym. You could not assume that all men are the same age. Thus, it would
be an inaccurate measure to state that “the average age of men who attend
Silver’s Gym is the same age as me.”
Averages are only one type of statistical measurements that may be of
interest. For example, your company likes to gauge sales during a certain time
of year and to keep costs low to a point that the business is making money.
These various statistical measurements are important in the world of statistics
because they help you make general conclusions about a given population or
sample.
To assist in your analysis for Silver’s Gym, answer the following questions
about the Body Fat Versus Weight data set:
Clickhere to download the Body Fat Weight data set.
The measures of central tendency are important in real-world situations.
Part II: Hypothesis Testing
Organizations sometimes want to go beyond describing the data and actually
perform some type of inference on the data. Hypothesis testing is a statistical
technique that is used to help make inferences about a population parameter.
Hypothesis testing allows you to test whether a claim about a parameter is
accurate or not.
Your boss makes the claim that the average body fat in men attending Silver’s
Gym is 20%. You believe that the average body fat for men attending Silver’s Gym
is not 20%. For claims such as this, you can set up a hypothesis test to reach
one of two possible conclusions: either a decision cannot be made to disprove
the body fat average of 20%, or there is enough evidence to say that the body
fat average claim is inaccurate.
To assist in your analysis for Silver’s Gym, answer the following questions
based on your boss’s claim that the mean body fat in men attending Silver’s Gym
is 20%: