IB Statistics and Probability Problem 016

Let the random variable X be normally distributed with a mean of \(25\), as shown in the figure below.

image essential to understanding the question

The shaded region between \(25\) and \(27\) represents \(30{\%}\) of the distribution.

  1. Find \(P(X > 27)\).
  2. Find the standard deviation of \(X\).
Published by Annie Bernatchez in «Statistics and Probability». Key Words: IB, question