Clevon forms a triangle with three straws measuring 20, 25, and 18 inches. To the nearest whole
1 answer:
Answer:
Step-by-step explanation:
Let's label this triangle as triangle ABC. Side AB is 18, side BC is 20 and side CA is 25 and the angle we are looking for is angle C. Use the Law of Cosines to find the missing angle. You have to use the Law of Cosines because in order to use the Law of Sines you have to have an angle given and we don't so we have no other options. In our case,
which for us looks like this:
and
and
and
and
Use the 2nd button and the cos button to find the missing angle.
Angle C = 45.4 which is, rounded to the nearest degree, 45°
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Answer:
Confidence =
And then the confidence level would be given by 99%
Step-by-step explanation:
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".
Assuming the X follows a normal distribution
The distribution for the sample mean is given by:
represent the sample mean
represent the population standard deviation
n= 100 sample size selected.
The confidence interval is given by this formula:
(1)
The marginof error for this case is given by Me=25.76. And we know that the formula for the margin of error is given by:
And we can find the critical value like this:
And we know that on the right tail of the z score =2.576 we have of the total area. We can find the area on the right of the z score using this excel code:
"=1-NORM.DIST(2.576,0,1,TRUE)" or using a table of the normal standard distribution, and we got 0.004998=, so then
, and then we can find the confidence like this:
Confidence =
And then the confidence level would be given by 99%