SmarterEd

Aussie Maths & Science Teachers: Save your time with SmarterEd

Algebra, STD2 A2 SM-Bank 3

The average height, `C`, in centimetres, of a girl between the ages of 6 years and 11 years can be represented by a line with equation

`C = 6A + 79`

where `A` is the age in years. For this line, the gradient is 6.

  1. What does this indicate about the heights of girls aged 6 to 11?   (1 mark)

  2. Give ONE reason why this equation is not suitable for predicting heights of girls older than 12.   (1 mark)

Show Answers Only
  1. `text(It indicates that 6-11 year old girls, on average, grow 6 cm per year.)`
  2. `text(Girls eventually stop growing, and the equation doesn’t factor this in.)`
Show Worked Solution

i.  `text(It indicates that 6-11 year old girls, on average, grow)`

`text(6 cm per year.)`
 

ii. `text(Girls eventually stop growing, and the equation doesn’t)`

`text(factor this in.)`