The answer to your question is A.
Answer:

Step-by-step explanation:
Given
See attachment for graph
Required
The unit cost
Pick any point on the dots of the graph; we have:

The unit cost is then calculated as:


Answer:
The z-score for SAT exam of junior is much small than his ACT score. This means he performed well in his ACT exam and performed poor in his SAT exam.
Step-by-step explanation:
Mean SAT scores = 1026
Standard Deviation = 209
Mean ACT score = 20.8
Standard Deviation = 4.8
We are given SAT and ACT scores of a student and we have to compare them. We cannot compare them directly so we have to Normalize them i.e. convert them into such a form that we can compare the numbers in a meaningful manner. The best way out is to convert both the values into their equivalent z-scores and then do the comparison. Comparison of equivalent z-scores will tell us which score is higher and which is lower.
The formula to calculate the z-score is:

Here, μ is the mean and σ is the standard deviation. x is the value we want to convert to z score.
z-score for junior scoring 860 in SAT exam will be:

z-score for junior scoring 16 in ACT exam will be:

The z-score for SAT exam of junior is much small than his ACT score. This means he performed well in his ACT exam and performed poor in his SAT exam.
Answer:
Step-by-step explanation:
The viniculum in a fraction represents subtraction with exponents.
Subtracting exponents gives us 3^12/3^8 * 3^2
Simplifying gives 3^12/3^10. Then, we can achieve 3^12 - 3^10.
This equals 3^2.
3^2 = 9.
So 9 is the answer of your question.
A negative cannot be a root, 8= 2.4