Answer:
The height is 18.5cm
Step-by-step explanation:
Given
Let
[tex]y =height[/tex]
[tex]x = time[/tex]
So, we have:
[tex](x_1,y_1) = (5,21.5)[/tex]
[tex](x_2,y_2) = (21,16.7)[/tex]
Required
The height after 15 hours
First, calculate the slope (m)
[tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]
This gives:
[tex]m = \frac{16.7-21.5}{21-5}[/tex]
[tex]m = \frac{-4.8}{16}[/tex]
[tex]m = -0.3[/tex]
The linear equation is then calculated as:
[tex]y =m(x - x_1) + y_1[/tex]
Where
[tex]m = -0.3[/tex]
[tex](x_1,y_1) = (5,21.5)[/tex]
This gives:
[tex]y =-0.3(x - 5) + 21.5[/tex]
Open bracket
[tex]y =-0.3x + 1.5 + 21.5[/tex]
[tex]y =-0.3x + 23[/tex]
After 15 hours
[tex]x = 15[/tex]
[tex]y =-0.3*15 + 23[/tex]
[tex]y =-4.5 + 23[/tex]
[tex]y =18.5[/tex]
The height is 18.5cm