Answer:
f(x) = 4x² - 40x + 84
Step-by-step explanation:
4(x - 7)(x - 3) = 0
4(x² - 3x - 7x + 21) = 0
4(x² - 10x + 21) = 0
4x² - 40x + 84 = 0
(11*5)+(4*10)=95
11+4=15
Both are equal to the constraints of the word problem and there for justified.
Answer:
The standard deviation of number of hours worked per week for these workers is 3.91.
Step-by-step explanation:
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by

After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X. Subtracting 1 by the pvalue, we This p-value is the probability that the value of the measure is greater than X.
In this problem we have that:
The average number of hours worked per week is 43.4, so
.
Suppose 12% of these workers work more than 48 hours. Based on this percentage, what is the standard deviation of number of hours worked per week for these workers.
This means that the Z score of
has a pvalue of 0.88. This is Z between 1.17 and 1.18. So we use
.





The standard deviation of number of hours worked per week for these workers is 3.91.
<span>Twelve diminished by six times a number</span>
<span> </span>
<span>12 - 6x </span>