Obstructive sleep apnea is a sleep disorder that causes a person to stop breathing momentarily and then awaken briefly. these sleep interruptions, which may occur hundreds of times a night, can drastically reduce the quality of rest and cause fatigue during waking hours. researchers at stanford university studied 159 commercial truck drivers and found that 124 of them suffered from obstructive sleep apnea. find a 99% confidence interval for the population proportion of commercial truck drivers that suffer from this sleep disorder.