In a certain neighborhood, the average number of candies received while trick-or-treating is 50, with a standard deviation of 12. If Isaac received 40 candies, calculate his z-score to the nearest thousandth(point)
To calculate Isaac's z-score, we use the formula:
z = (X - μ) / σ
where:
X = the value we are interested in (number of candies received by Isaac, which is 40)
μ = the mean (average number of candies received, which is 50)
σ = the standard deviation (which is 12)
Plugging in the values:
z = (40 - 50) / 12
z = -10 / 12
z = -0.83333 (rounded to the nearest thousandth)
Therefore, Isaac's z-score is approximately -0.833.