using Cohen's d. Also, calculate r2 for this problem. How large of an effect size is this, small, medium, or large?

A researcher is interested in whether or not children diagnosed with autism differ from other children in the number of digits from a list that they can correctly repeat back to the experimenter.  It is known that the average number of digits that children without autism in the population can repeat back is µ = 7.8.  A sample of 10 children with autism yielded the scores shown in the table below; the table shows how many digits each participant was able to repeat back to the experimenter.

Q. Continuing with this example, (i.e. the same population mean, etc.), calculate the effect size for the comparison of the autistic and non-autistic children, using Cohen's d.  Also, calculate r2 for this problem.  How large of an effect size is this, small, medium, or large