Step 1 :There are a total of 46 people in the school, which includes 6 administrators, 36 teachers, and 4 staff.
Step 2 :A committee of 3 people is to be formed randomly from these 46 people.
Step 3 :The total number of ways to form a committee of 3 people from 46 is given by the combination formula \(C(n, k) = \frac{n!}{k!(n-k)!}\), where \(n\) is the total number of people and \(k\) is the number of people in the committee. Substituting \(n = 46\) and \(k = 3\), we get \(C(46, 3) = 15180\) ways.
Step 4 :The number of ways to choose 3 administrators out of 6 is also given by the combination formula. Substituting \(n = 6\) and \(k = 3\), we get \(C(6, 3) = 20\) ways.
Step 5 :The probability that all 3 members are administrators is then the number of ways to choose 3 administrators divided by the total number of ways to form a committee. So, the probability is \(\frac{20}{15180} = 0.0013175230566534915\).
Step 6 :Rounding this to the nearest millionth, we get \(0.001317\).
Step 7 :Final Answer: The probability that all 3 members are administrators is approximately \(\boxed{0.001317}\).