Answer to Question #156017 in Statistics and Probability for domo

Question

A recent study found that the average cost of an emergency room visit was $1,200 with a standard deviation of $250. If a patient is selected at random, what is the probability that the person’s visit will cost more than $1,600?

Answer 1

This task will be solved with assumption of normal distribution.

$μ=1200 \\ σ = 250 \\ z = \frac{x-μ}{σ} \\ = \frac{1600-1200}{250} \\ = 1.60 \\ P(X>1600) = P(Z>1.60) \\ = 1 -P(Z<1.60) \\ = 1 -0.9452 \\ = 0.0548$

Answer: 0.0548 or 5.48 %