Answer:
a(a + 3b)
Step-by-step explanation:
a² + 2ab + ab
a² + 3ab
a(a + 3b)
Answer:
And if we solve for a we got
Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the hourly rates of a population, and for this case we know the distribution for X is given by:
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
Both conditions are equivalent on this case. We can use the z score again in order to find the value a.
As we can see on the figure attached the z value that satisfy the condition with 0.80 of the area on the left and 0.20 of the area on the right it's z=0.842. On this case P(Z<0.842)=0.8 and P(z>0.842)=0.20
If we use condition (b) from previous we have this:
But we know which value of z satisfy the previous equation so then we can do this:
And if we solve for a we got
Mike tosses 70%
Ike tosses 67%
Both tosses 50%
<span>Which of the following is closest to the probability that Ike's proportion is ringers is higher than Mike's for those tosses?
</span>
P(m) = 70/100
P(i) = 67/100
P(b) = 50/100
= P(b) * P(i)
= 50/100 * 67/100
= 0.335
The correct answer is letter D) 0.3745.