Home Price Test 6E5259
1. **State the problem:** We want to test if there is enough evidence to reject the claim that the average home price in Beaver County is $60,000 at significance level $\alpha = 0.05$.
2. **Set hypotheses:**
- Null hypothesis $H_0$: $\mu = 60000$
- Alternative hypothesis $H_a$: $\mu \neq 60000$ (two-tailed test)
3. **Calculate sample mean $\bar{x}$:**
Sum all prices and divide by 36.
4. **Calculate sample standard deviation $s$:**
Use formula $s = \sqrt{\frac{1}{n-1} \sum (x_i - \bar{x})^2}$.
5. **Calculate test statistic $t$:**
$$t = \frac{\bar{x} - \mu_0}{s/\sqrt{n}}$$
where $\mu_0 = 60000$, $n=36$.
6. **Find critical value:**
Degrees of freedom $df = n-1 = 35$.
At $\alpha=0.05$ two-tailed, critical $t_{0.025,35} \approx 2.030$.
7. **Decision rule:**
If $|t| > 2.030$, reject $H_0$; otherwise, do not reject.
8. **Calculate sample mean:**
Sum prices = 2,022,490
$$\bar{x} = \frac{2022490}{36} \approx 56180.28$$
9. **Calculate sample standard deviation:**
Calculate squared deviations, sum = 4,066,927,000
$$s = \sqrt{\frac{4066927000}{35}} \approx 10778.45$$
10. **Calculate test statistic:**
$$t = \frac{56180.28 - 60000}{10778.45/\sqrt{36}} = \frac{-3819.72}{1796.41} \approx -2.13$$
11. **Compare with critical value:**
$|t| = 2.13 > 2.030$, so reject $H_0$.
12. **Conclusion:**
There is sufficient evidence at the 0.05 level to reject the agent's claim that the average home price is $60,000$.