Final answer:
The question about Ava's scooter rides cannot be answered without knowing the total hours she rode. For the expected time for children to clean their rooms, it is 8 days based on uniform distribution between 1 to 15 days.
Step-by-step explanation:
The question is asking how many days Ava rode her scooter if she rode for 3/4 of an hour every day. However, to properly answer this question, we'd need to know the total hours Ava rode. If that's given, we can divide the total hours by 3/4 (or 0.75) to find out the total number of days. Regrettably, the question doesn't provide this necessary information, so we can't accurately answer without it.
To address the example related to children cleaning their rooms, the time it takes for children to clean their rooms is said to be uniformly distributed between one and 15 days. To find the expected value, or the average time, you would add the minimum time to the maximum time and divide by 2:
Expected waiting time = (Minimum time + Maximum time) / 2
Expected waiting time = (1 day + 15 days) / 2
Expected waiting time = 16 days / 2
Expected waiting time = 8 days