Answer:
21, 9
Step-by-step explanation:
If girls are x, then boys are x + 12
x + x + 12 = 30
2x + 12 = 30
2x = 18
x = 9
There are 9 girls and 21 boys
Answer:
30% probability that it will be yellow, or green
Step-by-step explanation:
The urn has red, white, blue, yellow, and green balls.
Each ball is chosen with the following probabilities:
1/10 = 10% probability it is red
2/5 = 40% probability it is white
1/5 = 20% probability it is blue.
p probability it is yellow or green
What is the probability that it will be yellow, or green
The sum of all probabilities is 100%. So
10 + 40 + 20 + p = 100
p = 30
30% probability that it will be yellow, or green
I believe the answer is x=0
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:
3rd one
Step-by-step explanation:
any 2 squares are congruent since all four sides of any square are congruent
