The answer would be 42 degrees because the total of a triangle is 180 degrees. So you would subtract 180 and 42 (180-42) and that gives you 138 and since the two angles that are touching are the same
If you're looking for an angle in between those, basically you have to choose an angle between 0 and 90°. any angle should work (such as 15°, 45°, 60°, 75°, etc.)
Considering the number of questions incorrect from classmates on a quiz {10, 11, 12, 13, 13, 13, 14, 15, 16, 16, 17, 18, 18, 19,
IrinaK [193]
Answer:
According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02
Step-by-step explanation:
We are given the following data in the question:
10, 11, 12, 13, 13, 13, 14, 15, 16, 16, 17, 18, 18, 19, 20
Formula:
where
are data points,
is the mean and n is the number of observations.
Sum of squares of differences = 25 + 16 + 9 + 4 + 4+ 4 + 1 + 0+ 1+ 1 + 4 + 9 + 9+ 16 + 25 = 128

Empirical rule:
- According to this rule almost all the data lies within three standard deviation of the mean for a normal distribution.
- About 68% of data lies within one standard deviation of the mean.
- About 95% of data lies within two standard deviations of mean.
- Arround 99.7% of data lies within three standard deviation of mean.
Thus, by empirical rule,

According to the Empirical Rule, 68% of the data should fall between 11.98 and 18.02
The answer is 40°
i will tell you how,
Total angle sum of any triangle is 180°
∠A + ∠B + ∠E = 180°
70° + 80° + ∠E = 180°
solve for ∠E
∠E = 30°
Now solve use ∠BDE,
∠B + ∠D + ∠E = 180°
20° + 90° + 30° + x = 180° (in triangle DEB, ∠E = 30 + x ) (∠D is 90°)
solve for x
there fore, x = 40°