# I have been given data that relates to the various strengths of mortar according to the amount of water that is used in the mix. .The data table shows the two features of the graph, one showing...

I have been given data that relates to the various strengths of mortar according to the amount of water that is used in the mix.

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The data table shows the two features of the graph, one showing the strength of the mortar , the other showing the % of water used in the mix.

I have been asked to plot the data on a suitably scaled and annotated graph. My problem is that I don’t know what to interpret as ‘suitably scaled’.

The strength ( all shown in tonnes)goes from 1.75--1.56--1.36--0.97--0.68--0.5--0.22

The % of water used goes from 5—7—9—13—16—18—21. ( the 5 obviously goes under the 1.75 and the rest progress accordingly)

What numbers would I use on this scale and which would go on the y and x axis?

Your help and advice on the best approach would be greatly appreciatd.

### 1 Answer | Add Yours

The data provided that relates the various strengths of mortar to the amount of water that is used in the mix.

Here, the amount of water used is the independent variable and the strength of the mortar is the dependent variable. Generally, the independent variable is plotted on the x-axis and the dependent variable is taken as y = f(x) and plotted on the y-axis.

A suitable scale would have to be used to accommodate all the values on the axes. Also, the values on neither axes have to start from 0; you could start plotting the values on the axes from a point that lies at the lowest value you have or slightly below it. That would avoid wasting space and give a clear graph.