Answer:
Required sample size is minimum 79
Step-by-step explanation:
Minimum sample size to estimate the true population mean is given by the formula:
N≥[tex](\frac{z*s}{E})^{2}[/tex] where
z=2.58 for 99% confidence level, s= 34.5 and E=10. If we put these numbers in the formula:
N≥[tex](\frac{2.58*34.5}{10}) ^{2}[/tex] =78.97 ≈ 79