Time(min) Length

0 12.5mm

5 30mm

10 50mm

How can i work out the growth rate per minute?

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- May 25th 2010, 10:26 PMel123Growth Rate
Time(min) Length

0 12.5mm

5 30mm

10 50mm

How can i work out the growth rate per minute? - May 26th 2010, 01:03 AMGrandad
Hello el123With more data, you could plot a graph, and draw tangents to the graph at the points where you wanted the growth rate. However, with this small amount of data, you can only work out average rates - there's not really enough data to plot a graph.

In the first $\displaystyle 5$ minutes the length has increased by $\displaystyle 30-12.5 = 17.5$ mm. So the average rate during this period is $\displaystyle \frac{17.5}{5}= 3.5$ mm per minute.

In the second $\displaystyle 5$ minutes, the length has increased by ...? So the average growth rate is ...?

And, overall, in $\displaystyle 10$ minutes the average growth rate is ... ?

Can you complete the calculations?

Grandad