Answer:
Part A. I chose points (7,1.3) and (48,9.8)
Part B. a. Positive correlation; b. y = 0.21x - 0.2
Step-by-step explanation:
Part A.
I chose the first and last points on the line — (7 in, 1.3 lb) and (48 in, 9.8 lb).
That put three points on the line, three above it, and four below.
Part B
a. Type of correlation
There is a positive correlation between the length of a puppy and its weight.
You would expect a longer dog to be bigger and weigh more than a shorter dog.
b. The equation for the line of best fit
The slope-intercept equation for a straight line is
y = mx + b
where m is the slope of the line and b is the y-intercept.
The line passes through the points (7,1.3) and (48, 9.8).
(i) Calculate the slope of the line
\begin{array}{rcl}
[tex]m & = & \dfrac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\ & = & \dfrac{9.8 - 1.3}{48-9}\\\\& = & \dfrac{8.5}{41}\\\\& = & \textbf{0.21 lb/in}\\\\\end{array}[/tex]
The slope of the line is 0.21 lb/in.
(ii) Locate the y-intercept
Put the slope and the coordinates of one point into the slope-intercept formula.
[tex]\begin{array}{rcl}y & = & mx + b\\1.3 & = & 0.21\times7 + b\\1.3 & = & 1.47 + b\\b & = & -0.2\\\end{array}[/tex]
The y-intercept is at (0,-0.2)
(iii) Write the equation for the line
y = 0.21x - 0.2
