Answer: The answer is the first explanation.
Step-by-step explanation: We are given five different options and we are to select which explanation is correct to derive the formula for a circumference of a circle.
Let 'C' be the circumference and 'd' be the diameter of a circle. Now, we will write the ratio of the circumference to the diameter as
Also, we know that
And diameter of a circle is twice the radius, so
Therefore,
This is the formula for the circumference of a circle. Since this explanation matches exactly with the first option, so the correct option is
(a). Find the relationship between the circumference and the diameter by dividing the length of the circumference and length of the diameter. Use this quotient to set up an equation to showing the ratio of the circumference over the diameter equals to π . Then rearrange the equation to solve for the circumference. Substitute 2 times the radius for the diameter.
Answer:
4????
Step-by-step explanation:
Answer:
The teacher can purchase 61 pencils with $5
Step-by-step explanation:
This is a simple proportion problem. It can be solved by pure logic reasoning without any formulas
It a dozen pencils cost $0.97, each pencil cost $0.97/12=0.08083
With $5 she will be able to purchase 5/0.08083=61.85 pencils
We must round to the nearest lower integer
The teacher can purchase 61 pencils with $5
Answer:
The slope of the line of best fit is 
⇒ 2nd option
Step-by-step explanation:
The formula of the slope of a line is 
<em>To find the slope of the best line fit choose two points their positions make the number of the points over the line equal to the number of the points below the line</em>
From the attached graph points (1 , 9) and (8 , 3) are the best choice
∵ The line passes through points (1 , 9) and (8 , 3)
∴ 
= 1 and 
= 8
∴ 
= 9 and 
= 3
- Substitute them in the formula of the slope
∴ 
∴ The slope of the line of best fit is
