Answer:
The z value is - 1.661538
Explanation:
The rule of the z-score for the population is z = ( x¯ - μ)/(σ/√n)
∵ x¯ = 128.60
∵ μ = 134
∵ σ = 26
∵ n = 64
- Substitute all of these values in the rule above to find z
∵

- Simplify up and down
∴

∴

∴ z = - 1.661538
The z value is - 1.661538