X = the number of humans and y = the number of horses.
x+y=74
2x+4y=196
Because the number of humans and horses together is 74, and the total number of legs (2 per every human, x, and 4 per every horse, y) is 196. Then, just use elimination to solve.
So, now that you have y, you can plug it into the first equation to find x:
So, x = 50 and y = 24, so there are 50 humans and 24 horses.
The correct answer is B.
I would help you but I can't see it maybe zoom in a little closer.
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:
Gets smaller
Step-by-step explanation:
- The standard deviation is the quantification of spread of data. According to descriptive statistics the standard deviation s is given by:
s = Σ ( x - u ) / sqrt ( n )
Where, n : sample size
u : Mean value
- So we see that standard deviation (s) is inversely proportional to square root of sample size (n).
- We can see that as sample size (n) increases the standard deviation (s) decreases.
