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:
When increasing the radius 3 times the volume increases 9 times and when it is reduced to a third the volume decreases 9 times
Step-by-step explanation:
We have that the formula for the volume of a cone is:
Vc = pi * (r ^ 2) * h
We first calculate the original volume, where the radius is 2 and the height is 9, replacing:
Vc = 3.14 * (2 ^ 2) * 9
Vc = 113.04
Now if the radius is tripled it would be: 2 * 3 = 6, the radius would be 6, replacing:
Vc = 3.14 * (6 ^ 2) * 9
Vc = 1017.36
If we compare:
1017.36 / 113.04 = 9
This means that when the radius is tripled, the volume increases 9 times.
When if re reduces to a third the radius would be: 2/3, replacing:
Vc = 3.14 * ((2/3) ^ 2) * 9
Vc = 12.56
113.04 / 12.56 = 9
Which means that by reducing it to a third the volume becomes 9 times smaller.
Answer:
True
Step-by-step explanation:
That is the definition of composite function
Sub x=-5+2y
2(-5+2y)+4y=14
y=3
Answer:
The car was travelling at a speed of 60 miles per hour.
Step-by-step explanation:
Given:
Distance traveled = 330 miles
Time Period = 
we need to find the speed of the car .
Solution:
Time Period =
Now we can say that;
So Time period = 
Now we know that;
Distance traveled 
is equal to Speed 
multiplied by Time Period 
.
framing in equation form we get;
Dividing both side by 5.5 we get;
Hence The car was travelling at a speed of 60 miles per hour.
