1. **State the problem:** We want to determine if the screening scores (Screen) are significantly correlated with the achievement scores (Achieve) using simple linear regression.
2. **Formula and explanation:** The simple linear regression model is given by:
$$y = \beta_0 + \beta_1 x + \epsilon$$
where $y$ is the dependent variable (Achieve), $x$ is the independent variable (Screen), $\beta_0$ is the intercept, $\beta_1$ is the slope, and $\epsilon$ is the error term.
3. **Calculate means:**
$$\bar{x} = \frac{1+3+3+3+5+6.5+6.5+8+9+10}{10} = \frac{55}{10} = 5.5$$
$$\bar{y} = \frac{46+52+41+92+59+48+66+82+41+60}{10} = \frac{587}{10} = 58.7$$
4. **Calculate slope $\beta_1$:**
$$\beta_1 = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sum (x_i - \bar{x})^2}$$
Calculate numerator:
$$\sum (x_i - 5.5)(y_i - 58.7) = (1-5.5)(46-58.7) + (3-5.5)(52-58.7) + (3-5.5)(41-58.7) + (3-5.5)(92-58.7) + (5-5.5)(59-58.7) + (6.5-5.5)(48-58.7) + (6.5-5.5)(66-58.7) + (8-5.5)(82-58.7) + (9-5.5)(41-58.7) + (10-5.5)(60-58.7)$$
Calculate each term:
$$( -4.5)(-12.7) = 57.15$$
$$( -2.5)(-6.7) = 16.75$$
$$( -2.5)(-17.7) = 44.25$$
$$( -2.5)(33.3) = -83.25$$
$$( -0.5)(0.3) = -0.15$$
$$(1)(-10.7) = -10.7$$
$$(1)(7.3) = 7.3$$
$$(2.5)(23.3) = 58.25$$
$$(3.5)(-17.7) = -61.95$$
$$(4.5)(1.3) = 5.85$$
Sum numerator:
$$57.15 + 16.75 + 44.25 - 83.25 - 0.15 - 10.7 + 7.3 + 58.25 - 61.95 + 5.85 = 33.5$$
Calculate denominator:
$$\sum (x_i - 5.5)^2 = (1-5.5)^2 + (3-5.5)^2 + (3-5.5)^2 + (3-5.5)^2 + (5-5.5)^2 + (6.5-5.5)^2 + (6.5-5.5)^2 + (8-5.5)^2 + (9-5.5)^2 + (10-5.5)^2$$
$$= 20.25 + 6.25 + 6.25 + 6.25 + 0.25 + 1 + 1 + 6.25 + 12.25 + 20.25 = 80$$
5. **Calculate slope:**
$$\beta_1 = \frac{33.5}{80} = 0.41875$$
6. **Calculate intercept $\beta_0$:**
$$\beta_0 = \bar{y} - \beta_1 \bar{x} = 58.7 - 0.41875 \times 5.5 = 58.7 - 2.303125 = 56.396875$$
7. **Regression equation:**
$$\hat{y} = 56.396875 + 0.41875 x$$
8. **Interpretation:** The positive slope indicates a positive correlation between Screen and Achieve scores.
9. **Significance test:** Calculate the correlation coefficient $r$ and test if it is significantly different from zero.
Calculate $r$:
$$r = \frac{\sum (x_i - \bar{x})(y_i - \bar{y})}{\sqrt{\sum (x_i - \bar{x})^2 \sum (y_i - \bar{y})^2}}$$
Calculate $\sum (y_i - \bar{y})^2$:
$$(46-58.7)^2 + (52-58.7)^2 + (41-58.7)^2 + (92-58.7)^2 + (59-58.7)^2 + (48-58.7)^2 + (66-58.7)^2 + (82-58.7)^2 + (41-58.7)^2 + (60-58.7)^2$$
$$= 161.29 + 44.89 + 313.29 + 1108.89 + 0.09 + 114.49 + 53.29 + 544.89 + 313.29 + 1.69 = 2709.1$$
Calculate $r$:
$$r = \frac{33.5}{\sqrt{80 \times 2709.1}} = \frac{33.5}{\sqrt{216728}} = \frac{33.5}{465.56} = 0.072$$
10. **Conclusion:** The correlation coefficient $r=0.072$ is very low, indicating a weak linear relationship. Statistical significance would require further hypothesis testing (e.g., t-test), but this low $r$ suggests Screen is not significantly correlated with Achieve.
**Final answer:** The regression equation is:
$$\hat{y} = 56.40 + 0.42 x$$
The correlation between Screen and Achieve is weak and likely not significant.
Screen Achieve Regression 8123Ca
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