2 A spinner has five sectors, each printed with a different colour. Susma and Sanjay both wish to test whether the spinner is biased so that it lands on red on fewer spins than it would if it were fair. Susma spins the spinner 40 times. She finds that it lands on red exactly 4 times.

1. Use a binomial distribution to carry out the test at the \(5 \%\) significance level.
   Sanjay also spins the spinner 40 times. He finds that it lands on red \(r\) times.
2. Use a binomial distribution to find the largest value of \(r\) that lies in the rejection region for the test at the 5\% significance level.