Given:
a.) Mean = 80
b.) Standard Deviation = 8
c.) Observed Value = 70
For us to be able to determine the z-score, we will be using the following formula:
[tex]\text{ Z - Score = }\frac{\text{ x - }\mu\text{ }}{\sigma}[/tex]Where,
x =observed value
μ = mean value
σ = standard deviation
We get,
[tex]\text{ Z - Score = }\frac{\text{ 70 - 80 }}{\text{ 8}}\text{ = }\frac{\text{ -10 }}{\text{ 8}}\text{ = -1.25}[/tex]Therefore, the z-score for 70 is -1.25
