Use the Empirircal Rule to answer this question

Question

Women in a survey spend an average of $246 per year on beauty supplies. If the distribution of women's spending is normally distributed and the standard deviation is $30. What percent spend less that $186 per year?

Answer 1

Empirical rule states that approximately 95% of the data will be between mean +/ 2SDs. In this case, approximately 95% spend fall between 246 +/- 2*30 = $246 +/- $60. So, 95% spend between $186 and $306. The remaining 5% spend outside this range -- 2.5% spend less than $186 and 2.5 % spend above $306.