Answer:
1. x = 1, -2
2. no solution
3. x = 6 -4
hope this helps!
Step-by-step explanation:
The line of best fit is a straight line that can be used to predict the
average daily attendance for a given admission cost.
Correct responses:
- The equation of best fit is;
![\underline{ \hat Y = 1,042 - 4.9 \cdot X_i}](https://tex.z-dn.net/?f=%5Cunderline%7B%20%5Chat%20Y%20%3D%201%2C042%20-%204.9%20%5Ccdot%20X_i%7D)
- The correlation coefficient is; r ≈<u> -0.969</u>
<h3>Methods by which the line of best fit is found</h3>
The given data is presented in the following tabular format;
![\begin{tabular}{|c|c|c|c|c|c|c|c|c|}Cost, (dollars), x&20&21&22&24&25&27&28&30\\Daily attendance, y&940&935&940&925&920&905&910&890\end{array}\right]](https://tex.z-dn.net/?f=%5Cbegin%7Btabular%7D%7B%7Cc%7Cc%7Cc%7Cc%7Cc%7Cc%7Cc%7Cc%7Cc%7C%7DCost%2C%20%28dollars%29%2C%20x%2620%2621%2622%2624%2625%2627%2628%2630%5C%5CDaily%20attendance%2C%20y%26940%26935%26940%26925%26920%26905%26910%26890%5Cend%7Barray%7D%5Cright%5D)
The equation of the line of best fit is given by the regression line
equation as follows;
Where;
= Predicted value of the<em> i</em>th observation
b₀ = Estimated regression equation intercept
b₁ = The estimate of the slope regression equation
= The <em>i</em>th observed value
![b_1 = \mathbf{\dfrac{\sum (X - \overline X) \cdot (Y - \overline Y) }{\sum \left(X - \overline X \right)^2}}](https://tex.z-dn.net/?f=b_1%20%3D%20%5Cmathbf%7B%5Cdfrac%7B%5Csum%20%28X%20-%20%5Coverline%20X%29%20%5Ccdot%20%28Y%20-%20%5Coverline%20Y%29%20%7D%7B%5Csum%20%5Cleft%28X%20-%20%5Coverline%20X%20%5Cright%29%5E2%7D%7D)
= 24.625
= 960.625
![\mathbf{\sum(X - \overline X) \cdot (Y - \overline Y)} = -433.125](https://tex.z-dn.net/?f=%5Cmathbf%7B%5Csum%28X%20-%20%5Coverline%20X%29%20%5Ccdot%20%28Y%20-%20%5Coverline%20Y%29%7D%20%3D%20-433.125)
Therefore;
![b_1 = \mathbf{\dfrac{-433.125}{87.875}} \approx -4.9289](https://tex.z-dn.net/?f=b_1%20%3D%20%5Cmathbf%7B%5Cdfrac%7B-433.125%7D%7B87.875%7D%7D%20%5Capprox%20-4.9289)
Therefore;
- The slope given to the nearest tenth is b₁ ≈ -4.9
![b_0 = \mathbf{\dfrac{\left(\sum Y \right) \cdot \left(\sum X^2 \right) - \left(\sum X \right) \cdot \left(\sum X \cdot Y\right)} {n \cdot \left(\sum X^2\right) - \left(\sum X \right)^2}}](https://tex.z-dn.net/?f=b_0%20%3D%20%5Cmathbf%7B%5Cdfrac%7B%5Cleft%28%5Csum%20Y%20%5Cright%29%20%5Ccdot%20%5Cleft%28%5Csum%20X%5E2%20%5Cright%29%20-%20%5Cleft%28%5Csum%20X%20%5Cright%29%20%5Ccdot%20%5Cleft%28%5Csum%20X%20%5Ccdot%20Y%5Cright%29%7D%20%7Bn%20%5Ccdot%20%5Cleft%28%5Csum%20X%5E2%5Cright%29%20-%20%5Cleft%28%5Csum%20X%20%5Cright%29%5E2%7D%7D)
By using MS Excel, we have;
n = 8
∑X = 197
∑Y = 7365
∑X² = 4939
∑Y² = 6782675
∑X·Y = 180930
(∑X)² = 38809
Therefore;
![b_0 = \dfrac{7365 \times 4939-197 \times 180930}{8 \times 4939 - 38809} \approx \mathbf{1041.9986}](https://tex.z-dn.net/?f=b_0%20%3D%20%5Cdfrac%7B7365%20%5Ctimes%204939-197%20%5Ctimes%20180930%7D%7B8%20%5Ctimes%204939%20-%2038809%7D%20%5Capprox%20%5Cmathbf%7B1041.9986%7D)
- The y-intercept given to the nearest tenth is b₀ ≈ 1,042
The equation of the line of best fit is therefore;
The correlation coefficient is given by the formula;
![\displaystyle r = \mathbf{\dfrac{\sum \left(X_i - \overline X) \cdot \left(Y - \overline Y \right)}{ \sqrt{\sum \left(X_i - \overline X \right)^2 \cdot \sum \left(Y_i - \overline Y \right)^2} }}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20r%20%3D%20%5Cmathbf%7B%5Cdfrac%7B%5Csum%20%5Cleft%28X_i%20-%20%5Coverline%20X%29%20%5Ccdot%20%5Cleft%28Y%20-%20%5Coverline%20Y%20%5Cright%29%7D%7B%20%5Csqrt%7B%5Csum%20%5Cleft%28X_i%20-%20%5Coverline%20X%20%5Cright%29%5E2%20%5Ccdot%20%5Csum%20%5Cleft%28Y_i%20-%20%5Coverline%20Y%20%5Cright%29%5E2%7D%20%7D%7D)
Where;
![\sqrt{\sum \left(X - \overline X \right)^2 \times \sum \left(Y - \overline Y \right)^2} = \mathbf{446.8121}](https://tex.z-dn.net/?f=%5Csqrt%7B%5Csum%20%5Cleft%28X%20-%20%5Coverline%20X%20%5Cright%29%5E2%20%5Ctimes%20%5Csum%20%5Cleft%28Y%20-%20%5Coverline%20Y%20%5Cright%29%5E2%7D%20%20%3D%20%5Cmathbf%7B446.8121%7D)
![\sum \left(X_i - \overline X \right) \times \left(Y - \overline Y\right) = \mathbf{-433.125}](https://tex.z-dn.net/?f=%5Csum%20%5Cleft%28X_i%20-%20%5Coverline%20X%20%5Cright%29%20%5Ctimes%20%5Cleft%28Y%20-%20%5Coverline%20Y%5Cright%29%20%3D%20%5Cmathbf%7B-433.125%7D)
Which gives;
![r = \dfrac{-433.125}{446.8121} \approx \mathbf{-0.969367213}](https://tex.z-dn.net/?f=r%20%3D%20%5Cdfrac%7B-433.125%7D%7B446.8121%7D%20%20%5Capprox%20%5Cmathbf%7B-0.969367213%7D)
The correlation coefficient given to the nearest thousandth is therefore;
- <u>Correlation coefficient, r ≈ -0.969</u>
Learn more about regression analysis here:
brainly.com/question/14279500
Slot method
8 optionns n 1st slot
7 options in 2nd slot (since 1 is at 1st slot)
6 options in 3rd slot
5 options in 4th slot
8*7*6*5=1680 ways