B It’s the one that makes sense
Answer:
x=5, y=8
Step-by-step explanation:
x+y=13
2x-y=2
add these two equations
3x=15
therefore x=5
apply this value in x+y=13
5+y=13
then y=13-5 = 8
The probability of picking a green marble the first time is 3/20 and the probability of picking a yellow marble the second time is 8/20.
probabilities are heavily related to percents so it would make sense that the probability of picking a color would be the number of that color divided by the total number.
note that it is really important that the problem said that the marble was replaced. If the marble was not replaced, the probability of picking a yellow marble the second time would be 8/19 if the first marble picked was not a yellow one.
I hope this helps.
Answer:
The interval [32.6 cm, 45.8 cm]
Step-by-step explanation:
According with the <em>68–95–99.7 rule for the Normal distribution:</em> If 
is the mean of the distribution and s the standard deviation, around 68% of the data must fall in the interval
![\large [\bar x - s, \bar x +s]](https://tex.z-dn.net/?f=%5Clarge%20%5B%5Cbar%20x%20-%20s%2C%20%5Cbar%20x%20%2Bs%5D)
around 95% of the data must fall in the interval
![\large [\bar x -2s, \bar x +2s]](https://tex.z-dn.net/?f=%5Clarge%20%5B%5Cbar%20x%20-2s%2C%20%5Cbar%20x%20%2B2s%5D)
around 99.7% of the data must fall in the interval
![\large [\bar x -3s, \bar x +3s]](https://tex.z-dn.net/?f=%5Clarge%20%5B%5Cbar%20x%20-3s%2C%20%5Cbar%20x%20%2B3s%5D)
So, the range of lengths that covers almost all the data (99.7%) is the interval
[39.2 - 3*2.2, 39.2 + 3*2.2] = [32.6, 45.8]
<em>This means that if we measure the upper arm length of a male over 20 years old in the United States, the probability that the length is between 32.6 cm and 45.8 cm is 99.7%</em>
