Unteers were divided into two equal-sized groups. each volunteer took a math test that involved transforming strings of eight digits into a new string that fit a set of given rules, as well as a third, hidden rule. prior to taking the test, one group received 8 hours of sleep, while the other group stayed awake all night. the scientists monitored the volunteers to determine whether and when they figured out the rule. of the volunteers who slept, 39 discovered the rule; of the volunteers who stayed awake, 15 discovered the rule. what can you infer about the proportions of volunteers in the two groups who discover the rule? support your answer with a 90% confidence interval.