Answer:
3rd option
Step-by-step explanation:
The equation of a parabola in vertex form is
f(x) = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k ) = (- 1, - 25 ) , then
f(x) = (x - (- 1) )² - 25 , that is
= (x + 1)² - 25 ← expand using FOIL
= x² + 2x + 1 - 25
= x² + 2x - 24
21/7=3mins per wall with 5 people.
Because we assume that all of the people paint at the same rate, 3 X 5=15 mins for one person working alone.
15/3=5 mins per wall with 3 people X 10 people= 50 mins for 3 people to paint 10 walls.
The answer is 50 mins.
95% of red lights last between 2.5 and 3.5 minutes.
<u>Step-by-step explanation:</u>
In this case,
- The mean M is 3 and
- The standard deviation SD is given as 0.25
Assume the bell shaped graph of normal distribution,
The center of the graph is mean which is 3 minutes.
We move one space to the right side of mean ⇒ M + SD
⇒ 3+0.25 = 3.25 minutes.
Again we move one more space to the right of mean ⇒ M + 2SD
⇒ 3 + (0.25×2) = 3.5 minutes.
Similarly,
Move one space to the left side of mean ⇒ M - SD
⇒ 3-0.25 = 2.75 minutes.
Again we move one more space to the left of mean ⇒ M - 2SD
⇒ 3 - (0.25×2) =2.5 minutes.
The questions asks to approximately what percent of red lights last between 2.5 and 3.5 minutes.
Notice 2.5 and 3.5 fall within 2 standard deviations, and that 95% of the data is within 2 standard deviations. (Refer to bell-shaped graph)
Therefore, the percent of red lights that last between 2.5 and 3.5 minutes is 95%
Answer:
x = 80°
Step-by-step explanation:
The full angle of the straight line is 180°. We already have 100°, so we need to find out what is left over for x
180 - 100 = 80
So the angle of x is 80°
Yes teachers say to do that all the time it helps you
