The problem asks us to take the given data, where "Hours Studying" is one variable and "Overall Class Performance" is another, and test if there is a statistically significant relationship between the two variables. We will test this using linear regression.

Probability and StatisticsLinear RegressionCorrelation Coefficientt-testStatistical SignificanceHypothesis Testing
2025/5/5

1. Problem Description

The problem asks us to take the given data, where "Hours Studying" is one variable and "Overall Class Performance" is another, and test if there is a statistically significant relationship between the two variables. We will test this using linear regression.

2. Solution Steps

We'll perform a linear regression analysis to determine if there's a statistically significant relationship between the hours spent studying and the overall class performance. We need to calculate the correlation coefficient rr, and perform a t-test to determine the statistical significance.
The data is:
Hours Studying (x): 0.62, 1.50, 0.34, 0.97, 3.54, 0.69, 1.53, 0.32, 1.94, 1.25, 1.42, 3.07, 3.99, 1.73, 1.90
Overall Class Performance (y): 1.02, 4.62, 1.60, 1.59, 4.67, 1.52, 2.28, 1.68, 2.50, 4.04, 2.63, 3.53, 3.90, 2.75, 2.95
First, we calculate the summary statistics:
n=15n = 15
xi=25.71\sum x_i = 25.71
yi=41.28\sum y_i = 41.28
xi2=61.867\sum x_i^2 = 61.867
yi2=133.2804\sum y_i^2 = 133.2804
xiyi=88.3514\sum x_i y_i = 88.3514
Next, we find the means:
xˉ=xin=25.7115=1.714\bar{x} = \frac{\sum x_i}{n} = \frac{25.71}{15} = 1.714
yˉ=yin=41.2815=2.752\bar{y} = \frac{\sum y_i}{n} = \frac{41.28}{15} = 2.752
Now we can calculate the correlation coefficient rr:
r=nxiyi(xi)(yi)[nxi2(xi)2][nyi2(yi)2]r = \frac{n\sum x_i y_i - (\sum x_i)(\sum y_i)}{\sqrt{[n\sum x_i^2 - (\sum x_i)^2][n\sum y_i^2 - (\sum y_i)^2]}}
r=15(88.3514)(25.71)(41.28)[15(61.867)(25.71)2][15(133.2804)(41.28)2]r = \frac{15(88.3514) - (25.71)(41.28)}{\sqrt{[15(61.867) - (25.71)^2][15(133.2804) - (41.28)^2]}}
r=1325.2711061.4408[928.005661.0041][1999.2061703.9184]r = \frac{1325.271 - 1061.4408}{\sqrt{[928.005 - 661.0041][1999.206 - 1703.9184]}}
r=263.8302[267.0009][295.2876]r = \frac{263.8302}{\sqrt{[267.0009][295.2876]}}
r=263.830278836.645=263.8302280.77860.94r = \frac{263.8302}{\sqrt{78836.645}} = \frac{263.8302}{280.7786} \approx 0.94
Now we perform a t-test to assess statistical significance:
t=rn21r2t = \frac{r\sqrt{n-2}}{\sqrt{1-r^2}}
t=0.941521(0.94)2t = \frac{0.94\sqrt{15-2}}{\sqrt{1 - (0.94)^2}}
t=0.941310.8836t = \frac{0.94\sqrt{13}}{\sqrt{1 - 0.8836}}
t=0.94(3.6056)0.1164t = \frac{0.94(3.6056)}{\sqrt{0.1164}}
t=3.38930.34129.93t = \frac{3.3893}{0.3412} \approx 9.93
Degrees of freedom df=n2=152=13df = n-2 = 15-2 = 13
Looking up the t-value of 9.93 with 13 degrees of freedom, we get a very small p-value (p < 0.001). Typically, we reject the null hypothesis if the p-value is less than 0.
0

5. Since our p-value is significantly less than 0.05, we reject the null hypothesis.

3. Final Answer

There is a statistically significant positive relationship between hours spent studying and overall class performance. The correlation coefficient is approximately 0.94, and the t-test results in a statistically significant result (p < 0.001).

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