Mrs. Ryan observed the relationshipbetween the number of tutorialsattended and semester grade for eachof the students in her Algebra Iclasses. The table below shows some ofthe resulting data.NumberotTutorialsAttended9SemesterGrade99491006378857761Which of the following shows anappropriate equation for the line ofbest fit?

Mrs Ryan observed the relationshipbetween the number of tutorialsattended and semester grade for eachof the students in her Algebra Iclasses The table below sho class=

Respuesta :

Answer:

y = 72.35 + 2.95x

Explanations:

Let the number of tutorials attended be represented by x

Let the semester grade be represented by y

x = { 9, 4, 0, 0, 6, 1}

y = {99, 91, 63, 78, 85, 77}

Calculate the mean of x

[tex]\begin{gathered} \bar{X}\text{ = }\frac{9+4+0+0+0+6+1}{5} \\ \bar{X}\text{ =}\frac{20}{6} \\ \bar{X}\text{ =}3.33 \end{gathered}[/tex]

Calculate the mean of y

[tex]\begin{gathered} \bar{Y}\text{ =}\frac{99+91+63+78+85+77}{6} \\ \bar{Y}\text{ = }\frac{493}{6} \\ \bar{Y}\text{ =}82.17 \end{gathered}[/tex][tex]m\text{ = }\frac{\sum ^n_{i\mathop=1}(x_i-\bar{X}\text{ )(y}_i-\bar{Y)}\text{ }}{\sum ^n_{i\mathop{=}1}(x_i-\bar{X}\text{ )}^2}[/tex][tex]\begin{gathered} m\text{ = }\frac{(9-3.33)(99-82.17)+(4-3.33)(91-82.17)+(0-3.33)(63-82.17)+(0-3.33)(78-82.17)+(6-3.33)(85-82.17)+(1-3.33)(77-82.17)}{\mleft(9-3.33\mright)^2+\mleft(4-3.33\mright)^2+(0-3.33)^2+(0-3.33)^2+(6-3.33)^2+(1-3.33)^2} \\ \text{m = }\frac{198.67}{^{}67.33} \\ \text{m = }2.95 \end{gathered}[/tex]

Calculate the y-intercept using the formula below:

[tex]\begin{gathered} b\text{ = }\bar{Y}-m\bar{X}\text{ } \\ \text{b = 82.17-2.95(3.33)} \\ \text{b = 82.17-}9.82 \\ b\text{ = }72.35 \end{gathered}[/tex]

The equation of a line is:

y = mx + b

Substitute m = 2.95 and b = 72.35 into the equation of a line given above:

y = 2.95x + 72.35