Answer:
The exact value of its surface area = 144π m²
The exact value of its volume = 288π m³
Step-by-step explanation:
∵ The diameter of the sphere is 12m
∴ The radius of the sphere = 12 ÷ 2 = 6m
∵ The surface area of the sphere = 4πr²
∴ The surface area = 4 × π × 6² = 144π m²
∵ The volume of the sphere = 4/3 πr³
∴ The volume = = 288π m³
Answer:
Here is the ans...hope it helps:)
Answer:
We need a sample size of at least 75.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, we find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
The standard deviation is the square root of the variance. So:
With a .95 probability, the sample size that needs to be taken if the desired margin of error is 5 or less is
We need a sample size of at least n, in which n is found when M = 5. So
We need a sample size of at least 75.