Review A-Level Edexcel Biology statistical tests through the available evidence on using correlation coefficients to judge relationship strength.
The drawing shows a speckled chicken. These chickens have a mixture of black and white feathers.
The colour of the feathers of a chicken is an example of codominance.
One parent of this speckled chicken had white feathers and the other parent had black feathers.
In an experiment, several pairs of speckled chickens were mated together.
They produced 480 chicks.
The table shows the expected number of speckled chicks, white chicks and black chicks. It also shows the actual number of each type of chick.
This table can be used in a statistics test.
Explain how a critical value table could be used to accept or reject a null hypothesis for this experiment.