Final answer:
To find the z-value for a given sample mean with known population parameters, use the formula z = (x - μ) / (σ / √n), substituting the appropriate values for x, μ, σ, and n.
Step-by-step explanation:
The student's question pertains to finding the z-value for a given sample mean (μ = 128.60) from a population where N = 10,000, the population mean (g) is 105, and the population standard deviation (o) is 10. When the sample size (n) is 25. The z-value is calculated using the formula:
z = (x - μ) / (σ / √n)
Where 'x' is the sample mean, 'μ' is the population mean, 'σ' is the population standard deviation, and 'n' is the sample size. Using the values provided and the formula for calculating the z-value, we can answer the student's question and explain how sample size affects the margin of error and resulting z-value calculations.