Answer:
Step-by-step explanation:
Let us assume that,
x represents the number of sq. yards of fabric and
y represents price of the fabric.
As the unit price of the fabric i.e cost per sq. yard of fabric is $1.25, so for each number of sq. yard of fabric, the cost for that much of fabric will be multiple of 1.25 of that number.
i.e
Here, the rate of change is 1.25. So for each increase in x, the amount of increase in y is 1.25
The table along with the graph have been attached below.
Answer:
--- Standard deviation
Step-by-step explanation:
Given
See attachment for graph
Solving (a): Explain how the standard deviation is calculated.
<u>Start by calculating the mean</u>
To do this, we divide the sum of the products of grade and number of students by the total number of students;
i.e.
So, we have:
Next, calculate the variance using the following formula:
i.e subtract the mean from each dataset; take the squares; add up the squares; then divide the sum by the number of dataset
So, we have:
Lastly, take the square root of the variance to get the standard deviation
--- approximated
<em>Hence, the standard deviation is approximately 11.28</em>
Considering the calculated mean (i.e. 82.76), the standard deviation (i.e. 11.28) is small and this means that the grade of the students are close to the average grade.
