Question

the graph shows the average length of a newborn baby, where x represents its age in months and y represents its length in inches. a line of best fit with equation y = 1.5x + 20 is also shown. according to the line of best fit, which statements are correct? select all that apply.
a the average length of a newborn baby at birth is 1.5 inches.
b the average length of a newborn baby at birth is 20 inches.
c for every week since birth, on average a newborn baby grows by 1.5 inches.
d for every week since birth, on average a newborn baby grows by 20 inches.
e for every month since birth, on average a newborn baby grows by 1.5 inches.
f for every month since birth, on average a newborn baby grows by 20 inches

Explanation:

Step1: Analyze the y - intercept

The equation of the line is \(y = 1.5x+20\). In the slope - intercept form \(y=mx + b\) (where \(m\) is the slope and \(b\) is the y - intercept), when \(x = 0\) (at birth, since \(x\) represents age in months), \(y=b\). Substituting \(x = 0\) into \(y=1.5x + 20\), we get \(y=20\). So the average length at birth is 20 inches.

Step2: Analyze the slope

The slope \(m = 1.5\). In the context of the problem, since \(x\) represents age in months, the slope \(m=\frac{\Delta y}{\Delta x}\) means that for every unit increase in \(x\) (every month), \(y\) (length) increases by \(m\) units. So for every month since birth, on average, a newborn baby grows by 1.5 inches.

Answer:

B. The average length of a newborn baby at birth is 20 inches; E. For every month since birth, on average a newborn baby grows by 1.5 inches.