Answer:
16%
Step-by-step explanation:
The indicated probability is actually the area under the standard normal curve to the left of the mean. I used the function normalcdf( on my TI-83 Plus calculator to find this quantity:
normalcdf(-1000,85,90,5) = 0.1587.
Note #1: This quantity (area / probability) is the area to the left of 85.
Note #2: by the Empirical Rule, 68% of data lies within 1 s. d. of the mean, so the area between the mean (90) and the score (85) is half of 68%, or 34%. Subtracting this from 50% (the area to the left of the mean), we get 16%, which is roughly equivalent to the 0.1587 we got earlier.
You just find the domain and the range and that’s it!
Answer:
x = 20
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Using ΔAHC , then
∠ACH = 180 - (2x + 100) = 180 - 2x - 100 = 80 - 2x
∠ECD = ∠ACB ( vertical angles are congruent ), thus
∠ECD = ∠ACH + ∠HCB, that is
3x = 80 - 2x + x
3x = 80 - x ( add x to both sides )
4x = 80 ( divide both sides by 4 )
x = 20