For the first is 3864
The second is 1320
A=3.14(which is pie) x 20.5^2
A=420x pie
A=1320
For the third is 2544
3864-1320=2544
Sorry if this is wrong too.
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%
Your answer would be (b.) because -2+-3=-5
A rectangular prism is a cuboid so volume of cuboid is base area x height which is 5x5x12=300
volume of pyramid is 1/3 x base area x height = 5x5x6x1/3=50 thus volume outside pyramid and inside cuboid is 300-50=250
The probability that the card is a football card is 20 out of 50 or 40%
the probability that the card is a basketball card is 10 out of 50 or 20%