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:
D. Batch 5.
Step-by-step explanation:
The batch should have the same proportion of blue to white to yellow.
In Batch 1, there are two parts of blue, 1.5 parts of white, and 1 part of yellow.
In Batch 5, there are four parts of blue, 3 parts of white, and 2 parts of yellow.
4 / 2 = 2
3 / 2 = 1.5
2 / 2 = 1
Since the proportions are equal to those found in Batch 1, D. Batch 5 will create the same colors as the first batch.
Hope this helps!
Answer:
B
Step-by-step explanation:
It's not a function because the X's repeat
