What is measurrment: KIH, JIH, KJI, and HKI?
1 answer:
<h3>Answer:</h3>
- KIH = 52.88°
- JIH = 105.50°
- KJI = 97.61°
- HKI = 43.12°
<em>The figure as drawn is impossible</em>. Taking the side lengths to be correct, triangle GIJ can be solved using the Law of Cosines. That solution can be used to solve triangle GJK using the angle at G and the Law of Sines.
The angle GJK, marked as 28°, is actually about 29.7767°.
The size of the angle at H (84°) ensures that the quadrilateral is <em>not cyclic</em>, so the solution of triangle HIK involves three simultaneous quadratic equations in the side lengths HI, GH, and HK (using the Law of Cosines).
I used a machine solver for that, with the results shown above.
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The figure shows the same result using a free geometry drawing program, GeoGebra. The tricky part is making sure the angle at H is 84°. That is done by making IK the chord of a circle through points H, I, K, such that the chord subtends an arc of 168°. The angle values shown on the figure are those measured by the drawing program.
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The value of mean, standard deviation and interval from the method of tree ring dating is 1273 AD, 37 years, [1250,1296].
According to the statement
we have to find that the standard deviation, mean and the intervals from the given data.
So, According to the given data from the method of tree ring dating
The value of mean is
x-bar = (1271 + 1208 + 1229 + 1299 + 1268 + 1316 + 1275 + 1317 + 1275) / 9 = x-bar = 1273 AD
And now we find standard deviation :
s = √∑(xi - x-bar) / (N - 1)
∑(xi - x-bar)^2 = (1271 - 1273)2 + (1208 - 1273)2 + (1229 - 1273)2 + ... + (1275 - 1273)2
∑(xi - x-bar)^2 = (-2)2 + (-65)2 + (-44)2 + ... + (2)2
∑(xi - x-bar)^2 = 4 + 4225 + 1936 + 676 + 25 + 1849 + 4 1936 + 4
∑(xi - x-bar)^2 = 10,659
Now,
s^2 = 10659/8 = 1332
s = 37 years
So, standard deviation is 37 years.
We need the t-distribution table since the standard deviation is unknown. Therefore, our degrees of freedom is 9 - 1 = 8 and the critical value is 1.860. Set up the confidence interval for the mean:
[x-bar ± t*(s/√n)] = [1273 ± 1.860*(37/√9)]
[x-bar ± t*(s/√n)] = [1250,1296]
So, The value of mean, standard deviation and interval from the method of tree ring dating is 1273 AD, 37 years, [1250,1296].
Learn more about method of tree ring dating here
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Question:
The method of tree ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution.
For more data please see the image below.
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