Answer:
- A. y = 91.1765x - 346.5708
- B. 64 lbs
Explanation:
Part A
Use the data in the table to get the best fit line, with equation:
To do so follow the steps:
1. Let the Height be x and the Weight be y
Sum x and y
- ∑x = 5.3 + 5.4 + 5.3 + 6 = 22
- ∑y = 140 + 150 + 130 + 200 = 620
2. Sum x² and xy
- ∑x² = 5.3² + 5.4² + 5.3² + 6² = 121.34
- ∑xy = 5.3*140 + 5.4*150 + 5.3*130 + 6*200 = 3441
3. Calculate m, considering n = 4 (number of data values)
- m = (n∑xy -∑x∑y)/(n∑x² - (∑x)²) =
- (4*3441 - 22*620)/(4*121.34 - 22²) =
- 124/1.36 = 91.1765
4. Calculate b:
- b = (∑y - m∑x)/n =
- (620 - 91.1765*22)/4 =
- -1385.883 /4 =
- -346.4708
We got the best line fit formula:
Part B
Finding y for x = 4.5:
- y = 91.1765*4.5 - 346.5708 = 63.72345 ≈ 64 lbs