Answer:
Margin of Error = ± 0.871
Step-by-step explanation:
The formula for Margin of Error = ± z × Standard deviation /√n
Where
Standard deviation = $1.85
n = Random number of samples = 30
z = z score for 99% confidence interval = 2.58
Hence,
Margin of Error = ± 2.58 × 1.85/√30
Margin of Error = ± 0.871426589
Approximately = ± 0.871
