1. 7.7 Line of Best Fit Solutions

2. A college record in the 100m dash in 1960(t) was 10.5 seconds (r). In 1990, the new record was 10.2. Assume a linear relationship fits the ordered pair (t, r), What is the linear equation to fit the data points? Predict what the record might be in the year 2000? t (year) Xr (Race Time) y 196010.5 199010.2 Make 1960 (X)= 0 and 1990 X=(3), 2000 (x=4) y = mx +b OR r = mt + b r = mt + b r = 10.1

3. A temperature of 0 o C is the same as 32 o F. A temperature of 10 o C is the same as 50 o F. Use the ordered pairs of (C, F) to find a linear relationship and the Fahrenheit temperature for 30 o C. C (X)F (Y) 032 1050 Boiling Water (100, 212)

4. For a ground temperature of 15 o C, the air temperature (t) at an altitude of 500m (h) is 10 o C. At 2000 m, the air temperature is -5 o C. Use the ordered pairs of (h, t) to find a linear equation and predict the air temperature at 1,500 m. H = height (X)T = Temp (Y) 015 50010 2000-5 y = 0

5. Scores on an achievement test (a) are related linearly to the scores on another test (b). Two students had the scores of: a=500, b=100 and a=680 and b=127. For the ordered pair (a, b), find the linear equation and predict the core on test (b) if the score on test (a) is 700. a (X)b (Y) 500100 680127

6. The total length (l) of a snake is related linearly to the length of the tail (t) of the snake. There are two snakes: Snake (1); 1=150mm and t=19mm. Snake (2); l = 300mm and t = 40 mm. Use the ordered pair (l, t) to find a linear relationship and find the length of a snake with a tail of 200mm. l (x)t (y) 15019 30040

7. Y Axis : Speed (s) 39105130204301394537? X Axis Year (y)18981904191019271935194719602000 1=18903812 Graph the ordered pairs (y, s) (year) and speed (s). Predict Speed for Year 2000: X Axis = Start at = 0= 1890 : Y Axis = 20 Units 1898 1904 1910 1960 1927 From 1960 to 2000 is 40 years. So: 40 * 8 = 320 more miles 1960 was 537 mph so 2000 will be 537 + 320 = 857

8. (x) Diameter (d) 4104035253520 (y) Age (y) 152015101520 Graph the ordered pairs (d, y) and draw a Line of Best Fit: 5 5 10 1520 25 35 30 10 15 20