Final answer:
The z-score for a sample with a mean of 68, from a population with a mean of 60 and a standard deviation of 10, using a sample size of 25, is calculated to be 4.
Step-by-step explanation:
The student's question concerns the calculation of a z-score for a sample mean in statistics. Given the sample mean (m), population mean (μ), population standard deviation (σ), and sample size (n), the z-score of the sample mean is calculated using the formula:
z = (m - μ) / (σ / sqrt(n))
In this case, with a sample of n=25, a sample mean of m = 68, a population mean of μ = 60, and a population standard deviation of σ = 10, we find:
z = (68 - 60) / (10 / sqrt(25))
z = 8 / (10 / 5)
z = 8 / 2
z = 4
The z-score for this sample is 4.