PLZ HELP AHHHH I NEED HELPEPWOEOW
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Answer:
So the value of height that separates the bottom 90% of data from the top 10% is 605.68.
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 heights of a population, and for this case we know the distribution for X is given by:
Where and
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 0.9 of the area on the left and 0.1 of the area on the right it's z=1.28. On this case P(Z<1.28)=0.9 and P(z>1.28)=0.1
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 90% of data from the top 10% is 605.68.
Answer:
16 cards
Step-by-step explanation:
We can use logic to find out how many cards were in the beginning.
If Ted took 6 cards, and Gina took half of what remained, then when Gina took cards, she had to choose from.
Now, Anna took of the cards, meaning that 12 is
of the amount of cards there originally were.
Hope this helped!