Linear Best Fit Models Look at the scatter plot to the right and make some observations.

Answer Scatter plots can be messy to understand. Some possible observations are that there is clustering around the 40-50 degree domain and 40-50 inches range. Clustering is a group of the same or similar elements occurring closely together.

Old Faithful It’s a geyser in Yellowstone National Park that shoots out hot water. Eruptions can shoot 3,700 to 8,400 US gallons of boiling water to a height of 106 to 185 feet lasting from 1.5 to 5 minutes. The average height of an eruption is 145 feet. The highest recorded eruption was 185 feet. Intervals between eruptions can range from 45 to 125 minutes, averaging 66.5 minutes in 1939, slowly increasing to an average of 90 minutes apart today. http://www.youtube.com/watch?v=tShhZvvIM84

Answer the following questions: (1) Where does the clustering take place. Why do you think this is. (2) Are there any outliers in the data? (3) Would you consider this a linear or non-linear pattern? (4) Is the line of best fit accurate for the data?

Answers (1) Where does the clustering take place. Why do you think this is. At 2 min. and 4.5 min. (2) Are there any outliers in the data? Several (3) Would you consider this a linear or non-linear pattern? Linear but could argue against (4) Is the line of best fit accurate for the data? Fairly accurate

Could you write an equation for the line of best fit Could you write an equation for the line of best fit? Think in terms of y= mx + b! Think of making a table to determine the slope and y-intercept. x y 45 1 2 55 3 65 4 75 5 90 so y = 10x + 45 approximately

PRACTICE PROBLEMS Page 392 1-10 (5 and 10 may be hard)