easy   Probability

Sturdy Roof II

A release-checked easy problem for training Central Limit Theorem.

Question

$100$ students are walking on the roof of a house. The weight of each student is random with mean $70$ kg and standard deviation $15$ kg, independently between students. Approximate the probability that the mean weight of the students exceeds $73$ kg. The answer will be in the form $\Phi(a)$ for some real $a$. Find $a$.

Practice focus

This Probability problem is tagged Central Limit Theorem. State the random variables and conditioning information explicitly, then check the result against boundary cases before opening hints or a solution.

Reviewed questions in this area

easyBaby BoyReviewed

Probability · SIG, DE Shaw

easyBad BagelReviewed

Probability · SIG, Jane Street