The perimeter of a rectangle is 40 inches. if its length is three times its width, find the dimensions.'
1 answer:
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Answer:
(1)
(2)
The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025,0,1)", and we got , replacing into formula (2) we got:
So the answer for this case would be n=25 rounded up to the nearest integer
Step-by-step explanation:
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)
represent the population standard deviation
n represent the sample size (variable of interest)
The confidence interval for the mean is given by the following formula:
The margin of error is given by this formula:
(1)
And on this case we have that ME =0.02 and we are interested in order to find the value of n, if we solve n from equation (1) we got:
(2)
The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025,0,1)", and we got , replacing into formula (2) we got:
So the answer for this case would be n=25 rounded up to the nearest integer
The <u>correct diagram</u> is attached.
Explanation:
Using technology (such as Geogebra), first construct a line segment. Name the endpoints C and D.
Construct the perpendicular bisector of this segment. Label the intersection point with CD as B, and create another point A above it.
Measure the distance from C to B and from B to D. They will be the same.
Measure the distance from A to B. If it is not the same as that from C to B, slide A along line AB until the distance is the same.
Using a compass and straightedge:
First construct segment CD, being sure to label the endpoints.
Set your compass a little more than halfway from C to D. With your compass set on C, draw an arc above segment CD.
With your compass set on D (the same distance as before) draw an arc above segment CD to intersect your first arc. Mark this intersection point as E.
Connect E to CD using a straightedge; mark the intersection point as B.
Set your compass the distance from C to B. With your compass on B, mark an arc on EB. Mark this intersection point as A.
AB will be the same distance as CB and BD.
Explanation:
Using technology (such as Geogebra), first construct a line segment. Name the endpoints C and D.
Construct the perpendicular bisector of this segment. Label the intersection point with CD as B, and create another point A above it.
Measure the distance from C to B and from B to D. They will be the same.
Measure the distance from A to B. If it is not the same as that from C to B, slide A along line AB until the distance is the same.
Using a compass and straightedge:
First construct segment CD, being sure to label the endpoints.
Set your compass a little more than halfway from C to D. With your compass set on C, draw an arc above segment CD.
With your compass set on D (the same distance as before) draw an arc above segment CD to intersect your first arc. Mark this intersection point as E.
Connect E to CD using a straightedge; mark the intersection point as B.
Set your compass the distance from C to B. With your compass on B, mark an arc on EB. Mark this intersection point as A.
AB will be the same distance as CB and BD.