2.  A line of best fit is a line that follows the pattern of the data. It goes through or close to as many of the data values as possible.  For each line of best fit there are confidence values for how accurately the line matches the data. There are 4 main confidence values: No correlation Weak Strong Very Strong

3. In addition to confidence values for the line of best fit on a scatter plot we also have what is called correlation values. The correlation is the direction of the slope: Practice: Tell what confidence and correlation the scatter plots have. 1. 2.

5. Review writing equations of linear lines  Remember Linear Lines mean straight lines  The basic formula for all linear lines is y=mx+b  m=slope and b=y-intercept  There are 3 main ways to find slope: 1. Counting from a graph. Always read a graph From left to right (just like a book). 2. Formula: 3. Solving an equation for y=mx+b form (we will look at this method more in depth soon).

6. Practice: Finding slope 1) 4)

7. Warm-up  Create a box and whisker plot for the following set of data: 86, 98, 73, 75, 23, 81, 60, 89, 93, 82 2030405060708090100

9.  Using lines of best fit to predict or project what will happen if the trend of the line continues. 1. Draw the line of best fit 2. What type of correlation and how strong is it? 3. Given the equation y=5x +60 predict Predict the grade for someone who studies For 6 hours. 4. What do the slope (5/1) and y-int (60) Mean in terms of the problem? 5. Is there any correlation between The number of hours studied and the Grade on the final exam? 1 2 3 4 5 6 60 65 70 75 80 85 90 95 Hours Studied Grade