Can someone please help
1 answer:
You might be interested in
Answer:
The minimum sample size needed is . If n is a decimal number, it is rounded up to the next integer.
is the standard deviation of the population.
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 Z-table as such z has a p-value of .
That is z with a pvalue of , so Z = 1.645.
Now, 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.
How large a sample must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?
A sample of n is needed, and n is found when M = 4. So
The minimum sample size needed is . If n is a decimal number, it is rounded up to the next integer.
is the standard deviation of the population.