Final answer:
To be 93% confident with a margin of error of 0.05, the survey agency would need to select a sample size of approximately 330 students.
Step-by-step explanation:
To determine the sample size needed to estimate a population proportion with a desired level of confidence and margin of error, we can use the formula:
n = (Z^2 * p * (1-p)) / E^2
Where:
- n is the sample size
- Z is the Z-score corresponding to the desired level of confidence (in this case, for a 93% confidence level, Z = 1.8119)
- p is the estimated proportion (in this case, p = 0.5)
- E is the desired margin of error (in this case, E = 0.05)
Using these values in the formula, we get:
n = (1.8119^2 * 0.5 * (1-0.5)) / 0.05^2 = 329.2861
Therefore, to be 93% confident with a margin of error of 0.05, the survey agency would need to select a sample size of approximately 330 students.