We are given with
Confidence interval of 95%. This corresponds to a Z value of 1.96
Margin of error, d = 1 inch
Population standard deviation, σ = 2.415 inch
We can calculate for the sample size using the formula
n = Z² σ² / d²
Substituting,
n = 1.96² (2.415)² / 1²
n = 22.4 ~ 23
