2.4 Trends, Interpolation and Extrapolation

Line of Best Fit a line that approximates a trend for the data in a scatter plot shows pattern and direction

Line of Best Fit a line that approximates a trend for the data in a scatter plot shows pattern and direction

How to Find the Line of Best Fit The line of best fit should: – pass through as many points as possible – allow remaining points to be grouped equally above and below the line

Draw the line of best fit for the following scatter plots:

Why make a Line of Best Fit?  Helps us to make predictions by  INTERPOLATING  EXTRAPOLATING

Interpolating: Estimating a value BETWEEN two measurements in a set of data Extrapolating: Estimating a value BEYOND the range of a set of data

Interpolating – what would the wife’s age be of a husband who is 57? Extrapolating - what would the wife’s age be of a husband who is 84?

The table below shows the sales of bottled water at a refreshment booth at the Canadian National Exhibition in Toronto for different days during a heat wave one summer. Temperature (°C) Bottles Sold Dependent variable: Bottles sold Independent Variable: Temperature

Describe the relationship between the variables. – The warmer it is outside the more bottles of water you sell. d) Identify any outliers. Should they be included in the data set? – (let’s discuss) e) What does the ordered pair (29, 147) mean? – remember (x,y)!!!!

“ Outlier” Order pair (29,147)

Predict how many bottles of water will be sold on a day when the temperature reaches 25°C. This is an example of ___________________. g) Predict how many bottles of water will be sold on a day when the temperature reaches 42°C. This is an example of ___________________. HW. p. 73 #2, 4, 6-8