Final answer:
On average, there are 5,000 visitors to the museum each day it is open, which is calculated by dividing the annual visitor count by the number of days open. However, without specific arrival patterns, it's not possible to give a precise number of average visitors at a given time.
Step-by-step explanation:
To find the average number of visitors in the museum on a given day, we first calculate the daily visitors based on the annual visitor count and the number of days the museum is open. With 1,500,000 visitors per year and the museum being open 300 days a year, we get 5,000 visitors per day on average (1,500,000 visitors / 300 days = 5,000 visitors/day).
Given that each visitor spends an average of 2 hours in the museum and the museum is open for 8 hours a day (from 9 a.m. to 5 p.m.), we can estimate how evenly spaced out the visitors might be. However, without information on the pattern of arrivals throughout the day (e.g. more visitors in the morning vs. the afternoon), we cannot accurately determine the average number of visitors present at any given minute without making broad assumptions.