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:
6 ways
Step-by-step explanation:
Given:
Books: Spanish, Maths and History textbooks (1 each)
Required
Determine the number of arrangements
In total, Nathan has 3 books.
The number of arrangements (n) is as follows:
The first book can be lined in 3 ways
The second book can be lined in 2 ways
The third book can be lined in 1 way
So,


Answer:
I say C. Because 2 shows up twice for the bag of beans
Step-by-step explanation:
Answer:
216:6 ratio
36 rate
Step-by-step explanation:
B -4-1 because the one is positive and the 4 is negative