# Causal relation

• Jun 14th 2005, 10:21 AM
catparker5
Lord this is killing me, someone help!
Ok here is my delima, I know absolutely nothing about trig, algebra or calculus and I have assignments due that I cant not answer and when I do, they are wrong. I graduated high school in 1990 and we did not have someo f this and it has been soooooooo long ago. Can someone help me please??? Here are the questions...

In the real world, what might be a situation where it is preferable for the data to form a relation but not a function?

If the variables in an equation were reversed, what would happen to the graph of the equation? For example, how would the graph of y = x² relate to the graph of x = y²? When might such a reversal of variables be useful in the real world?

You have been invited to present statistical information at a conference. To prepare, you must perform the following tasks:

Search the Internet and the Cybrary to find the number of deaths in the United States due to each of the following medical conditions in each of these years; 1985, 1990, 1995, and 2002.:
heart disease
cancer
AIDS
Plot your data for each disease as points in a rectangular coordinate system.
Using a smooth line, connect your data points for each disease graph.
Using each curve, make a reasonable prediction as to the number of deaths we might expect in 2005 due to each of these medical conditions.

Follow-up questions:

Please include responses to these questions with your submission.

Can the graphs that you constructed be classified as functions? Explain.
Why is it reasonable that negative numbers are excluded from both the domain and the range of each of the disease graphs? What would the real-world implications be if these numbers were actually part of the domain and/or range?

Catherine
• Jun 15th 2005, 01:31 PM
Math Help
relation vs function
When you say that a drug makes people feel better and you want to convey that information it is difficult with a function to say with x amount of drug the patient feels y amount better. But you can argue that there is a strong positive relationship between taking a drug and feeling better.

If the variables in an equation were reversed, the function is mirrrored about the line y=x, graph it and you will understand.

This is usefull when you want to change the relationship of cause and effect. Such as are people buying a certain stock because its price is going up or is the price going up because people ar buying the stock. you can switch x and y to see the different relationships graphically.