Thread: linear graph theory

data provided the height of a child over time

• Age months 11,12,14.5,17,25.5,30,36,48,60,72,84,108

• heiught cm 71.5,72,74,81,86,90,93.6,102.6,108,114.3,119.4,130 .8

Questions
draw a scatter diagram with the independant variable on the horizontal axis
draw a line of best fit through your scatter
find the equation of your line of best fit
write down the gradient of the line and explain this
predict childs height when age is 120 months using excel and explain it

Are you doing this manually, or are you using a graphing calcuator?

I never do these things manually. They take too long.

Using a TI-84+ calculator, I got

y=.6154154546x+68.70123287 as the equation of the line of best fit. The gradient is the coefficient of x.

For f(120), I got 142.55109 cm for height at 120 months