Answer:
94
Step-by-step explanation:
Margin of error = E = $ 120
Confidence Level = 95%
The z-score for 95% confidence level from the z-table = z = 1.96
Population standard deviation = σ = $593
Sample size = n = ?
The formula to calculate the margin of error is:
Re-arranging the equation, we get:
Using the given values in above equation, we get:
Rounding of to next higher integer, we get n = 94
Thus, we need a sample size of 94 to estimate an unknown population mean μ