It’s my final Test please help
1 answer:
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Answer:
And if we solve for a we got
So the value of height that separates the bottom 20% of data from the top 80% is 23.432.
Step-by-step explanation:
Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:
Where and
For this part we want to find a value a, such that we satisfy this condition:
(a)
(b)
As we can see on the figure attached the z value that satisfy the condition with 0.20 of the area on the left and 0.80 of the area on the right it's z=-0.842
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
So the value of height that separates the bottom 20% of data from the top 80% is 23.432.
Answer:
(-4, 5)
Step-by-step explanation (work shown in attached picture):
1) Since x is already isolated in the first equation, substitute that value for x into the other equation to find y. So, substitute 16-4y for the x in 3x + 4y = 8, then solve for y. This gives us y = 5.
2) Now, substitute that given value for y back into any one of the equations to find x. I chose to do it in the first equation. Substitute 5 for the y in x = 16-4y, then solve for x this time. This gives us x = -4.
Since x = -4 and y = 5, the solution is (-4, 5).
