Answer:
609
Step-by-step explanation:
Standard deviation = = $30
Margin of error = E = $2
Confidence level = 90%
Since the distribution is said to be normal, we will use z scores to solve this problem.
The z score for 90% confidence level = z = 1.645
Sample size= n = ?
The formula to calculate the margin of error is:
Using the values in above equation, we get:
This means, the minimum number of observations required is 609
Answer:
1). Because whole number doesn’t allow decimal numbers.
2). Because whole number doesn’t allow negative numbers. It starts with 0, 1, 2, 3....
Answer:
1187.52
Step-by-step explanation:
A=2πrh+2πr2=2·π·9·12+2·π·92≈1187.52202