Answer:
C.
Step-by-step explanation:
(I MAY BE WRONG) srry if I was
We can solve the problem by two methods: Synthetic division and long division.
Synthetic division:
-3 | 1 0 1 0 -2
-3 9 -30 90
---------------------------
1 -3 10 -30 88
The remainder is 88.
By long division:
h^3 -3h^2 + 10h -30
---------------------------------------
x + 3 | h^4 + 0h^3 + h^2 + 0h -2
h^4 + 3h^3
----------------
-3h^3 + h^2 + 0h -2
-3h^3 -9h^2
-------------------------------
10h^2 + 0h -2
10h^2 +30h
-----------------------
-30h - 2
-30h -90
--------------
88
The remainder is 88
Cross multiply
10 x 9 = 90
3 x k = 3k
make an equality
90 = 3k
divide both sides by 3
90/3 = k
simplify
30 = k
Answer:
And we can find this probability using the normal standard table or excel and we got:
The figure shows the calculation for this case.
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 hardness of a population, and for this case we know the distribution for X is given by:
Where and
We are interested on this probability
And the best way to solve this problem is using the normal standard distribution and the z score given by:
If we apply this formula to our probability we got this:
And we can find this probability using the normal standard table or excel and we got:
The figure shows the calculation for this case.