QUESTION 4 Sleep apnoea is a sleep disorder that causes a person to stop breathing momentarily and then awaken briefly. A study of 474 Victorian commercial truck drivers found that 98 of them suffered from sleep apnoea. Use the survey results to estimate, with 93% confidence, the proportion of Victorian commercial truck drivers who suffer from this sleeping disorder. Report the upper bound of the interval only, giving your answer as a percentage to two decimal places.

Fig: 1