Liam works at a zoo. He was looking at some data showing the masses of their 5555 African elephants. The mean mass of the elepha
1 answer:
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Answer:
So the answer for this case would be n=65 rounded up to the nearest integer
And the sample size would decrease by 160-65=95 subjects
Step-by-step explanation:
1) Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
represent the sample mean for the sample
population mean (variable of interest)
s represent the sample standard deviation
n represent the sample size
ME represent the margin of error
The confidence interval for the mean is given by the following formula:
(1)
2) Solution to the problem
Since the new Confidence is 0.90 or 90%, the value of and
, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.05,0,1)".And we see that
Assuming that the deviation is known we can express the margin of error is given by this formula:
(a)
And on this case we have that ME =\pm 3 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
Replacing into formula (b) we got:
So the answer for this case would be n=65 rounded up to the nearest integer
And the sample size would decrease by 160-65=95 subjects
Answer:
Yes,planner has met the minimum height, as minimum height was 9 feet and maximum height of arc is 9.6 feet
Step-by-step explanation:
The question is incomplete as all the details have not been given in the question.I have attached the complete question and its options at the bottom. Consult in for better understanding.
As we can see that at the mid value, for x=4, the value of f(x)=9.4
It means that the maximum height occurs at mid of the arc where it is height is 9.6 feet above the ground.
It means that the planner has met the minimum height, as minimum height was 9 feet and maximum height of arc is 9.6 feet
