Home Price Test 25E15E
1. **State the problem:** We want to test if there is enough evidence to reject the claim that the average price of a home sold in Beaver County is $60,000 at a significance level of $\alpha = 0.05$.
2. **Set up hypotheses:**
- Null hypothesis $H_0$: $\mu = 60000$
- Alternative hypothesis $H_a$: $\mu \neq 60000$ (two-tailed test)
3. **Calculate sample mean $\bar{x}$ and sample standard deviation $s$:**
Given the 36 home prices, calculate:
$$\bar{x} = \frac{\sum x_i}{n}$$
$$s = \sqrt{\frac{1}{n-1} \sum (x_i - \bar{x})^2}$$
4. **Calculate the test statistic $t$:**
$$t = \frac{\bar{x} - \mu_0}{s / \sqrt{n}}$$
where $\mu_0 = 60000$, $n=36$.
5. **Find critical value:**
Degrees of freedom $df = n-1 = 35$. For $\alpha=0.05$ two-tailed, critical $t$ value $\approx \pm 2.030$.
6. **Decision rule:**
- If $|t| > 2.030$, reject $H_0$.
- Otherwise, do not reject $H_0$.
7. **Calculate sample mean:**
Sum of prices = 2,022,490
$$\bar{x} = \frac{2022490}{36} \approx 56180.28$$
8. **Calculate sample standard deviation $s$:**
Calculate each $(x_i - \bar{x})^2$, sum them, divide by 35, then take square root.
Sum of squared deviations $\approx 3.44 \times 10^{10}$
$$s = \sqrt{\frac{3.44 \times 10^{10}}{35}} \approx 31368.5$$
9. **Calculate test statistic:**
$$t = \frac{56180.28 - 60000}{31368.5 / \sqrt{36}} = \frac{-3819.72}{5228.08} \approx -0.73$$
10. **Compare with critical value:**
$|t| = 0.73 < 2.030$, so we do not reject $H_0$.
**Final conclusion:** There is not enough evidence at the 0.05 significance level to reject the agent's claim that the average home price is $60,000$.