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Median Fit Method

You light a candle and record its height in cm every minute. You observe the following data.

time (min)	1	2	3	4	5	6	7	8	9
height (cm)	15	14	13.5	13	12.6	12.1	11.3	10.8	10

Plot the points and use a ruler to draw the media fit line. What is the slope of that line? What does this represent in terms of the candle?

Procedure:

Plot the points
Separate points into 3 equal groups
Find median of each group
Connect 2 outside medians w/ dotted line
draw a line parallel to the line in step 3, 1/3 of the way towards the middle median

point 1 (2.2, 14)
point 2 (6.7, 11.5)
m= $\frac{y_2-y_2}{x_2-x_1}=\frac{11.5-14}{6.7-2.2}=\frac{-2.5}{4.5}=\frac{-5}{9}$
$\frac{-5}{9}$ represents the fact that the candle gets 5cm shorter every 9 minutes