<h3>
Answer: 48</h3>
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Explanation:
Triangle ABC is isosceles because AC = BC.
The angles opposite these congruent sides are angle ABC and angle BAC. These are the base angles.
For any isosceles triangle, the base angles are congruent.
Angle BAC = 69 degrees is given. So angle ABC = 69 as well.
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The missing angle must add to the two other angles so that all three angles in a triangle add to 180
(angle ABC) + (angle BAC) + (angle BCA) = 180
69 + 69 + (angle BCA) = 180
138 + (angle BCA) = 180
angle BCA = 180-138
angle BCA = 42
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Angle DCE is congruent to angle BCA because they are vertical angles.
Triangle DCE is a right triangle. The missing angle is 90-(angle BCA) = 90-42 = 48
angle EDC = 48 degrees
Answer:
a) 
b)
c)
Step-by-step explanation:
Assuming the following question: Because of staffing decisions, managers of the Gibson-Marimont Hotel are interested in the variability in the number of rooms occupied per day during a particular season of the year. A sample of 20 days of operation shows a sample mean of 290 rooms occupied per day and a sample standard deviation of 30 rooms
Part a
For this case the best point of estimate for the population variance would be:

Part b
The confidence interval for the population variance is given by the following formula:
The degrees of freedom are given by:
Since the Confidence is 0.90 or 90%, the significance
and
, the critical values for this case are:
And replacing into the formula for the interval we got:
Part c
Now we just take square root on both sides of the interval and we got:
It’s the first one on the top left corner
Answer:
180º
Step-by-step explanation:
All the interior angles add up to 180º degrees.
Since the side which measures 10 is a vertical projection of the hipotenuse x on a 20 degree angle:
10 = x*sin(20°)
x = 29.238044
Since we have to round to the nearest hundreth:
x = 29.24 m