As you know, height is the dependent variable. Mean values for height would be listed in the right column. Our data are in rows, with the dependent variable in the bottom row.
Highlight the information in the two rows (including the headings) and select Insert/Chart... from the top menu or click on the Chart Wizard icon. Notice that the first (active) cell is unshaded.
Choose the plot type XY (Scatter) and keep the default sub-type. Hit the Next button to see a preview of the graph, then hit Finish. The program is designed to recognize whether you put your data into rows or columns, but in case of a mistake you should double check that it made the correct choice.
Now, is the graph that appeared good enough, or will you want to make changes?
good enough
make changes
Time is the independent variable, to be plotted on the x axis; height (a measured quantity) is a dependent variable, to be plotted on the y axis.
A good choice for plotting these data is to use a scatter plot (XY scatter) of mean values verus time, rather than a scatter plot of raw data; other plot types are not suitable for this kind of data set.