Question: Suppose we want to know whether or not the mean weight of a certain species of turtle is equal to 310 pounds. To test this, we will perform a one-sample t-test at significance level $\alpha = 0.05$.
a. State the Null Hypothesis and Identify the claim: (2pts)
H₀: ________________________________________________
H₁: ________________________________________________
b. Set the Level of Significance: (1pt)
$\alpha$: __________________
c. Calculate the t-critical Value ($t_{critical}$) (2pts)
$t_{critical}$: __________________
d. Compute the one sample t-test Value: (5pts)
e. Decision Rule (draw the bell curve): (10pts)
f. State the Conclusion: (5pts)
1. **Problem Statement:** We want to test if the mean weight $\mu$ of a species of turtle is equal to 310 pounds using a one-sample t-test at significance level $\alpha = 0.05$.
2. **Hypotheses:**
- Null hypothesis $H_0$: $\mu = 310$ (the mean weight is 310 pounds).
- Alternative hypothesis $H_1$: $\mu \neq 310$ (the mean weight is not 310 pounds).
3. **Level of Significance:**
- Given $\alpha = 0.05$.
4. **Formula for t-test statistic:**
$$t = \frac{\bar{x} - \mu_0}{s / \sqrt{n}}$$
where:
- $\bar{x}$ = sample mean
- $\mu_0$ = hypothesized population mean (310 pounds)
- $s$ = sample standard deviation
- $n$ = sample size
5. **Calculate the critical t-value:**
- For a two-tailed test at $\alpha = 0.05$, the critical values are $\pm t_{\alpha/2, df}$ where $df = n-1$.
- Use a t-distribution table or calculator with degrees of freedom $df$.
6. **Compute the t-test value:**
- Substitute the sample statistics into the formula.
- Show intermediate steps including simplification and cancellation if any.
7. **Decision Rule:**
- If $|t| > t_{critical}$, reject $H_0$.
- Otherwise, fail to reject $H_0$.
8. **Conclusion:**
- Based on the decision rule, state whether there is enough evidence to conclude the mean weight differs from 310 pounds or not.
*Note:* Since the problem does not provide sample data ($\bar{x}$, $s$, $n$), the numerical calculation of $t$ and $t_{critical}$ cannot be completed here.
**Summary:**
- $H_0: \mu = 310$
- $H_1: \mu \neq 310$
- $\alpha = 0.05$
- $t = \frac{\bar{x} - 310}{s/\sqrt{n}}$
- Decision: reject $H_0$ if $|t| > t_{critical}$
This completes the setup and explanation for the one-sample t-test for the turtle mean weight problem.