- A1/4, because the spinner has no memory of the spins that came before
- B1/1024, because that is the chance of five reds in a row
- CLess than 1/4, because red is now due to stop appearing
- DMore than 1/4, because the spinner has shown that it favours red
Step-by-Step Solution
The spins are independent, so what has already happened cannot alter what the spinner does next: the fifth spin stops on red with probability 1/4, exactly as the first did. The value is the probability of five reds in a row BEFORE any spinning starts; once four reds have already been seen, four of those five factors have been settled and only the last one is still uncertain. 'Red is due to stop' is the gambler's fallacy — a fair spinner keeps no account to settle, and the long-run balance is restored by later spins swamping the early ones, not by them being corrected. 'The spinner favours red' would be a fair suspicion about a spinner that might be biased, but the question states that the four sectors are equal, so the model is given and four spins is far too little evidence to overturn it.
Answer: A) 1/4, because the spinner has no memory of the spins that came before