Solution: We are given:

Using the empirical rule, we have:
covers 68% of data.
Also the percentage of values below mean = Percentage of values above mean = 50%
Now, let's find the z score for x=20

Therefore, the percentage of values greater than 1 standard deviation above mean 
Expected number of students = 16% of 100 = 16
Answer:
BC < ED ⇒ answer A
Step-by-step explanation:
* Lets revise some facts in the triangle
- If one side of a triangle is longer than another side, then the angle
opposite the longer side will be larger than the angle opposite the
shorter side
- If one angle in a triangle is larger than another angle in a triangle,
then the side opposite the larger angle will be longer than the side
opposite the smaller angle
* Lets solve the problem
- In the two triangles BCD and DEB
∵ CD = 8 and BE = 8
∴ CD = BE
∵ Side BD is a common side in the two triangles
- The third side in Δ BCD is BC and the third side in DEB is DE
∵ BC is the opposite side to the angle of measure 24°
∵ ED is the opposite side to the angle of measure 30°
∵ The measure 24° < the measure 30°
∴ The side opposite to the angle of measure 24° < the side opposite
to the angle of measure 30°
∵ The other two sides of the 2 triangles BCD and DEB are equal
∴ We can compare between the 3rd sides in the Δ BCD and Δ DEB
∴ BC < ED
Answer:
Step-by-step explanation:
y = -
x + 3 ( equation of line t )
y - (- 2) = -
[ x - (- 2)] ⇒ y = -
x -
( equation of line u )