Question

What is the z-score for Σx = 1,186?

Short answer

The Z- score is approximately$-1$

Step-by-step solution

Given Information

According to the Given details, the sample size of customers is 1186 with a mean 3 and the standard deviation is $0.7$.

Explanation

The sum of values is 840, so the$Z$-score is given as:

$\sum X=\left(n\right)\left({\mu }_X\right)+\left(z\right)\left(\sqrt{n}\right)\left({\sigma }_X\right)$

$1186=400\times 3+\left(z\right)\times \sqrt{400}\times 0.7$

$-14=14.0\left(z\right)$

$z=-1$