Using the given data you can build the linear regression (described by linear function y=ax+b) by hand or you can use math calculator to do this. In attached diagram you can see that

and

Then the equation of linear function is

Answer: correct choice is D.
<span>Understand that:
• the sum of two positive numbers is greater than either
number.
Understand that addition is the inverse of subtraction (addition
reverses subtraction and vice versa) and use this to check
results.
Respond rapidly to oral or written questions, explaining the
strategy used. For example:
• 654 add 50… Add 68 to 74…
• 7 add 12 add 9… Add 15, 6, 4, 15 and 1…
• What is the sum/total of 26 and 39? And of 13, 62 and 3?
• How many altogether are 121 and 35? And 61, 37 and 6?
• Increase 48 by 22.
• Which three numbers could have a total of 103?
Are there any others?</span>
Arc length of the quarter circle is 1.57 units.
Solution:
Radius of the quarter circle = 1
Center angle (θ) = 90•
Arc length = 1.57 units
Arc length of the quarter circle is 1.57 units.