if we take 4100 to be the 100%, what is 870 off of it in percentage?
this just wants us to calculate 4/5-1/3
make common denom
4/5 times 3/3=12/15
1/3 times 5/5=5/15
4/5-1/3=12/15-5/15=(12-5)/15=7/15
7/15lb is left
Answer:
A) 1/(3x+1)
Step-by-step explanation:
(x+2)/(x³+2x²-9x-18)÷(3x+1)/(x²-9)
(x+2)/(x+2)(x+3)(x-3)÷(3x+1)/(x+3)(x-3)
since it’s dividing by a fraction, invert and multiply
(x+2)/(x+2)(x+3)(x-3) times (x+3)(x-3)/(3x+1)
The (x+2)’s cancel out.
The (x+3)’s cancel out.
The (x-3)’s cancel out.
You are left with 1/(3x+1)
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%
