Questions: A nutritionist claims that the mean tuna consumption by a person is 3.5 pounds per year. A sample of 90 people shows that the mean tuna consumption by a person is 3.4 pounds per year. Assume the population standard deviation is 1.11 pounds. At α=0.07, can you reject the claim?
(a) Identify the null hypothesis and alternative hypothesis.
A. H0: μ>3.5 B. H0: μ ≤ 3.5 Ha: μ ≤ 3.5 Ha: μ>3.5
C. H0: μ>3.4 Ha: μ ≤ 3.4
D. H0: μ=3.5 Ha: μ ≠ 3.5
E. H0: μ ≠ 3.4 Ha: μ=3.4
F. H0: μ ≤ 3.4 Ha: μ>3.4
(b) Identify the standardized test statistic, z.
z= (Round to two decimal places as needed.)
(c) Find the P-value.
Hint: Keep in mind that P-value depends on the type of test.
Left-tailed test: P-value=Area
Right-tailed test: P-value=1-Area
Transcript text: A nutritionist claims that the mean tuna consumption by a person is 3.5 pounds per year. A sample of 90 people shows that the mean tuna consumption by a person is 3.4 pounds per year. Assume the population standard deviation is 1.11 pounds. At $\alpha=0.07$, can you reject the claim?
(a) Identify the null hypothesis and alternative hypothesis.
A. $\mathrm{H}_{0}: \mu>3.5$ B. $H_{0}: \mu \leq 3.5$ $H_{a}: \mu \leq 3.5$ $\mathrm{H}_{\mathrm{a}}: \mu>3.5$
C. $\mathrm{H}_{0}: \mu>3.4$ $\mathrm{H}_{a}: \mu \leq 3.4$
D. $\mathrm{H}_{0}: \mu=3.5$ $H_{a}: \mu \neq 3.5$
E. $\mathrm{H}_{0}: \mu \neq 3.4$ $\mathrm{H}_{\mathrm{a}}: \mu=3.4$
F. $\mathrm{H}_{0}: \mu \leq 3.4$ $\mathrm{H}_{\mathrm{a}}: \mu>3.4$
(b) Identify the standardized test statistic, z.
$z=$ $\square$ (Round to two decimal places as needed.)
(c) Find the P-value.
Hint: Keep in mind that P-value depends on the type of test.
Left-tailed test: P-value=Area
Right-tailed test: $\mathbf{P}$-value=1-Area
Solution
Solution Steps
Step 1: Hypotheses
We set up the null and alternative hypotheses as follows:
Null Hypothesis: \( H_0: \mu = 3.5 \)
Alternative Hypothesis: \( H_a: \mu \neq 3.5 \)
Step 2: Standardized Test Statistic
To calculate the standardized test statistic \( z \), we use the formula:
\[
z = \frac{X - \mu}{\sigma}
\]
where:
Calculating \( z \):
\[
z = \frac{3.4 - 3.5}{0.1170} \approx -0.85
\]
Step 3: P-value Calculation
Since this is a two-tailed test, we calculate the P-value as:
\[
P\text{-value} = 2 \times (1 - P(Z \leq z))
\]
Using the cumulative distribution function (CDF) for the standard normal distribution, we find:
\[
P\text{-value} \approx 1.6047
\]
Step 4: Decision
We compare the P-value to the significance level \( \alpha = 0.07 \):
Since \( P\text{-value} \approx 1.6047 > 0.07 \), we fail to reject the null hypothesis.
Final Answer
The null hypothesis cannot be rejected, indicating that there is not enough evidence to dispute the nutritionist's claim.