NEED HELP ASAP PLEASE
2 answers:
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Answer:
So the answer for this case would be n=2663 rounded up to the nearest integer
Step-by-step explanation:
We have the following info:
margin of error desired
the standard deviation for this case
The margin of error is given by this formula:
(a)
And on this case we have that ME =50 and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
The critical value for 99% of confidence interval now can be founded using the normal distribution. The significance is . And for this case would be
, replacing into formula (b) we got:
So the answer for this case would be n=2663 rounded up to the nearest integer
Answer:
The guy wire lenght is 500 ft.
Step-by-step explanation:
The Pythagorean Theorem says the sum of the squares two adyacent sides is equal to the square of the opposite side.
Applied in this example, we can rephrase it as:
The sum of the square of the pylon height with the square of the distance from the guy wire tip to the pylon is Equal to the square of the Guy wire lenght.
So:
We will use trigonometric identities to solve this. I will use θ (theta) for the angle.
First of all, we know that cotθ = 1/tanθ. This is a trigonometric identity.
We can replace cotθ in the expression with 1/tanθ.
Simplify: 1/tanθ * tanθ = tanθ/tanθ = 1
So now, we have:
Next, we also know that secθ = 1/cosθ. This is another trigonometric identity.
We can replace secθ with 1/cosθ in our expression.
Simplify:
Our third trigonometric identity that we will use is tanθ = sinθ/cosθ.
We can replace sinθ/cosθ with tanθ.
Now we have as our final answer:
Hope this helps!