$A$ primary root grows from $5 \, cm$ to $19 \, cm$ in a week. Calculate the growth rate and relative growth rate over the period.

(N/A) Growth is measured by the increase in size over time.
$1$. Absolute Growth Rate: This is the total growth per unit time.
Absolute Growth Rate = $\frac{\text{Final size} - \text{Initial size}}{\text{Time}} = \frac{19 \, cm - 5 \, cm}{7 \, days} = \frac{14 \, cm}{7 \, days} = 2 \, cm/day$.
$2$. Relative Growth Rate: This is the growth per unit initial size per unit time.
Relative Growth Rate = $\frac{\text{Growth}}{\text{Initial size}} = \frac{19 \, cm - 5 \, cm}{5 \, cm} = \frac{14}{5} = 2.8$.
Thus, the absolute growth rate is $2 \, cm/day$ and the relative growth rate is $2.8$.