Answer:
5/21.
Step-by-step explanation:
Total number of balls = 7.
Prob(Blue on first pick) = 3/7
Prob(Blue on second pick) = 2/6 = 1/3
So Prob( 2 Blue's) = 3/7 * 1/3 = 3/21 = 1/7.
Prob(Red on first pick) = 2/7
Prob(Red on second pick) = 1/6
So Prob( 2 Red's) = 2/7 * 1/6 = 1/21.
Now the Probability of getting 2 white balls is the same as for the red balls
= 1/21.
Finally, the probability of 2 balls of the same colour
= 1/7 + 1/21 + 1/21
= 3/21 + 1/21 + 1/21
= 5/21.
Square root of 18 because it's the only irrational number.
The answer is B!
I could explain further if needed!
In case the user wants to see workings. These problems can easily be solved on a calculator, but can we work them out in our heads? ;)
9.34-3.029
=9.340-3.029
=9.340-3.000-0.029
=6.340-0.029
=6.311
Using the Empirical Rule, it is found that the proportion of people in a population with IQ scores between 80 and 140 is of 0.95 = 95%.
<h3>What does the Empirical Rule state?</h3>
It states that, for a normally distributed random variable:
- Approximately 68% of the measures are within 1 standard deviation of the mean.
- Approximately 95% of the measures are within 2 standard deviations of the mean.
- Approximately 99.7% of the measures are within 3 standard deviations of the mean.
Considering the mean of 110 and the standard deviation of 15, we have that:
These values are both the most extreme within 2 standard deviations of the mean, hence the proportion of people in a population with IQ scores between 80 and 140 is of 0.95 = 95%.
More can be learned about the Empirical Rule at brainly.com/question/24537145
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