I would say A (7) but I’m not 100% sure.
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:
You would have to subtract 7/10
Step-by-step explanation:
87/10 - 7/10 would equal 8
Answer:
28
Step-by-step explanation:
p(x)=-2(x-9)^2+100
Let x= 15
p(15)=-2(15-9)^2+100
Parentheses first
= -2 ( 6) ^2 + 100
Then exponents
= -2 * 36 + 100
Then multiply
= -72 + 100
Then add
=28
I think the last one is the right one
