Questions: Given in the table are the BMI statistics for random samples of men and women. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a 0.05 significance level for both parts.
Male BMI Female BMI
---------
**μ** μ₁ μ₂
**n** 48 48
**x̄** 27.4282 26.0503
**s** 8.538108 5.185315
State the conclusion for the test.
A. Fail to reject the null hypothesis. There is not sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
B. Fail to reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
C. Reject the null hypothesis. There is not sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
D. Reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
b. Construct a confidence interval suitable for testing the claim that males and females have the same mean BMI.
<μ₁-μ₂<
Transcript text: Given in the table are the BMI statistics for random samples of men and women. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a 0.05 significance level for both parts.
\begin{tabular}{|c|c|c|}
\hline & Male BMI & Female BMI \\
\hline $\boldsymbol{\mu}$ & $\mu_{1}$ & $\mu_{2}$ \\
\hline $\boldsymbol{n}$ & 48 & 48 \\
\hline$\overline{\boldsymbol{x}}$ & 27.4282 & 26.0503 \\
\hline $\mathbf{s}$ & 8.538108 & 5.185315 \\
\hline
\end{tabular}
State the conclusion for the test.
A. Fail to reject the null hypothesis. There is not sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
B. Fail to reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
C. Reject the null hypothesis. There is not sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
D. Reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
b. Construct a confidence interval suitable for testing the claim that males and females have the same mean BMI.
$\square$
$\square$
$<\mu_{1}-\mu_{2}<$
Solution
Solution Steps
Step 1: Calculate the Standard Error
The Standard Error \( (SE) \) is calculated using the formula:
The critical value for a two-tailed test at a significance level of \( \alpha = 0.05 \) with \( df \approx 47 \) is:
\[
\text{Critical value} \approx 2.0117
\]
Step 6: Conclusion of the Hypothesis Test
Since the p-value \( (0.0) \) is less than the significance level \( (0.05) \), we reject the null hypothesis. Thus, there is sufficient evidence to warrant rejection of the claim that men and women have the same mean BMI.
Step 7: Construct the Confidence Interval
The confidence interval for the difference in means is calculated as follows:
\[
(\bar{x}_1 - \bar{x}_2) \pm z \cdot SE = (27.4282 - 26.0503) \pm 1.96 \cdot 1.0201
\]
Calculating the interval gives:
\[
(-1.448, 4.204)
\]
Final Answer
The conclusion for the test is: \\(\boxed{D}\\).
The confidence interval for the difference in means is: \\(\boxed{(-1.448, 4.204)}\\).