Review A-Level Edexcel Biology dispersion, standard deviation and range through the available evidence on mean-and-range calculations in inhibition-zone data.
This photograph, taken through a light microscope, shows three of the stomata on the underside of a leaf.
The area of a sample of pores in fossil leaves was investigated and the means calculated.
These means were correlated with estimates of atmospheric carbon dioxide concentration at the time the fossil was formed.
The results are shown in the table.
The data in the table were plotted on a graph.
Atmospheric carbon dioxide concentration / ppm
Draw the standard deviation for the mean area of the pores and on the graph.