Assignment 9

We talked about most of this in class. Be careful on number 5: how are slope and correlation related? Think about it. Is it possible that a graph could have points NOT close together and another graph have points that ARE close together, yet the "best fit line" had the same slope?

Another hint is that r values can only take on certain numbers. What number is the slope?

Questions 7-9 we talked about in class. Look back to your notes on correlation, "r". Each one of the rules we discussed falls into one of these phrases.
Correlation coefficient:

• has no units
• is effected by outliers
• can only be between quantitative variables
• only describe linear relationships
  
• is between -1 and 1
  

Question 12 uses the slope definition. Here is a reminder of that definition:

"The average change in y for every one unit increase in x".

All of the red variables can be exchanged for the specific circumstance.

Good Luck!
-Hillary