1. **Problem statement:** We want to test the hypothesis that gender (Køn) and sport participation (Sport) are independent.
2. **Hypotheses:**
- Null hypothesis $H_0$: Gender and sport are independent.
- Alternative hypothesis $H_1$: Gender and sport are dependent.
3. **Data from the table:**
\begin{align*}
&\text{Sport Yes (Ja)}: \text{Boys (Dreng)} = 1590, \text{Girls (Pige)} = 1451, \text{Total} = 3041 \\
&\text{Sport No (Nej)}: \text{Boys} = 116, \text{Girls} = 146, \text{Total} = 262 \\
&\text{Total Boys} = 1706, \text{Total Girls} = 1597, \text{Grand Total} = 3303
\end{align*}
4. **Test used:** Chi-square test for independence.
5. **Expected counts under $H_0$:**
$$ E_{ij} = \frac{(\text{row total}) \times (\text{column total})}{\text{grand total}} $$
Calculate expected counts:
- $E_{\text{Ja, Dreng}} = \frac{3041 \times 1706}{3303} = \frac{5189246}{3303} \approx 1570.5$
- $E_{\text{Ja, Pige}} = \frac{3041 \times 1597}{3303} = \frac{4854977}{3303} \approx 1470.5$
- $E_{\text{Nej, Dreng}} = \frac{262 \times 1706}{3303} = \frac{447572}{3303} \approx 135.5$
- $E_{\text{Nej, Pige}} = \frac{262 \times 1597}{3303} = \frac{418114}{3303} \approx 126.5$
6. **Calculate Chi-square statistic:**
$$ \chi^2 = \sum \frac{(O - E)^2}{E} $$
Where $O$ is observed count and $E$ is expected count.
Calculate each term:
- $\frac{(1590 - 1570.5)^2}{1570.5} = \frac{19.5^2}{1570.5} = \frac{380.25}{1570.5} \approx 0.242$
- $\frac{(1451 - 1470.5)^2}{1470.5} = \frac{(-19.5)^2}{1470.5} = \frac{380.25}{1470.5} \approx 0.259$
- $\frac{(116 - 135.5)^2}{135.5} = \frac{(-19.5)^2}{135.5} = \frac{380.25}{135.5} \approx 2.806$
- $\frac{(146 - 126.5)^2}{126.5} = \frac{19.5^2}{126.5} = \frac{380.25}{126.5} \approx 3.005$
Sum:
$$ \chi^2 = 0.242 + 0.259 + 2.806 + 3.005 = 6.312 $$
7. **Degrees of freedom:**
$$ df = (\text{rows} - 1)(\text{columns} - 1) = (2-1)(2-1) = 1 $$
8. **Critical value at 5% significance level:**
From chi-square table, $\chi^2_{0.05,1} = 3.841$
9. **Decision:**
Since $6.312 > 3.841$, we reject $H_0$.
10. **Conclusion:**
There is sufficient evidence at the 5% significance level to conclude that gender and sport participation are dependent.
Chi Square Test Ff2E65
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