Shirley wants to find the distance her unicycle moves on the sidewalk when the tire makes one complete revolution. If the diamet
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Answer:
So on this case the 95% confidence interval would be given by (38.608;39.392)
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=25 represent the sample size
Solution to the problem
The confidence interval for the mean is given by the following formula:
(1)
The margin of error is given by:
Since the Confidence is 0.95 or 95%, the value of and
, and we can use excel, a calculator or a tabel to find the critical value. The excel command would be: "=-NORM.INV(0.025,0,1)".And we see that
And replacing we got:
Now we have everything in order to replace into formula (1):
So on this case the 95% confidence interval would be given by (38.608;39.392)
the length of the side of this square is cm
Answer:
Solutions Given:
let diagonal of square be AC: 8 cm
let each side be a.
As diagonal bisect square.
let it forms right angled triangle ABC .
Where diagonal AC is hypotenuse and a is their opposite side and base.
By using Pythagoras law
hypotenuse ²=opposite side²+base side²
8²=a²+a²
64=2a²
a²=
a²=32
doing square root on both side
a=±
a=±2*2
Since side of square is always positive so
a=4 or 5.65 cm
