A random sample of leading companies in South Korea gave the following percentage yields based on assets. 2.7 1.7 4,4 1.1 0.1 3.6 2.4 0.2 1.7 1.8 1.4 5.4 1.1 Use a calculator to verify that s = 2.449 for these South Korean companies. Another random sample of leading companies in Sweden gave the following percentage yields based on assets. 2.1 3.3 3.1 1.6 3.4 2.8 2.3 3.5 2.8 Use a calculator to verify that s? s 0.420 for these Swedish companies. Test the claim that the population variance of percentage yields on assets for South Korean companies is higher than that for companies in Sweden. Use a 5% level of significance. How could your test conclusion relate to an economist's question regarding volatility of corporate productivity of large companies in South Korea compared with those in Sweden? (a) What is the level of significance? State the null and alternate hypotheses. O H;: 0,? = 0,²; H;: 01 > 0, O H,: 0, > 0,²; H,: 0,2 = 0,2 O Ho: 0,? = 0,?; H;: 0,² > o,? O H,: 0,? = 0,²; H,: 0,? + 0,? (b) Find the value of the sample F statistic. (Use 2 decimal places.) What are the degrees of freedom? dfo What assumptions are you making about the original distribution? O The populations follow dependent normal distributions. We have random samples from each population. The populations follow independent chi-square distributions. We have random samples from each population. O The populations follow independent normal distributions. We have random samples from each population. The populations follow independent normal distributions. (c) Find or estimate the P-value of the sample test statistic.

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### Analysis of Variance in Corporate Productivity

A random sample of leading companies in South Korea provided the following percentage yields based on assets:

- 2.7, 1.7, 4.4, 1.1, 0.1, 3.6, 2.4
- 0.2, 1.7, 1.8, 1.4, 5.4, 1.1

Using a calculator, the variance \( s^2 \approx 2.449 \) for these South Korean companies.

Another sample from leading companies in Sweden provided these yields:

- 2.1, 3.3, 3.1, 1.6, 3.4, 2.8, 2.3, 3.5, 2.8

The variance is \( s^2 \approx 0.420 \) for these Swedish companies.

#### Hypothesis Testing

To test if the population variance of percentage yields for South Korean companies is higher than that for Swedish companies, we use a 5% level of significance. This relates to understanding volatility in corporate productivity between South Korea and Sweden.

**(a) What is the level of significance?**

*Answer:* 5%

**State the null and alternate hypotheses:**

- \( H_0: \sigma_1^2 = \sigma_2^2 \)
- \( H_i: \sigma_1^2 > \sigma_2^2 \)

**(b) Calculate the Sample F Statistic:**

Find the value of the sample F statistic using two decimal places. This involves the formula for comparing two variances:

\[ F = \frac{\text{Variance of South Korean companies}}{\text{Variance of Swedish companies}} \approx \frac{2.449}{0.420} \]

**Degrees of Freedom:**

- \( df_N \) (numerator): Sample size minus one for South Korean companies.
- \( df_D \) (denominator): Sample size minus one for Swedish companies.

**What assumptions are made about the original distributions?**

Option: The populations follow independent normal distributions. We have random samples from each population.

**(c) Find the P-value for the sample test statistic.**

Compute this using the F-distribution tables or statistical software.

### Conclusion

This test helps determine if there is a statistically significant difference in variance between the
Transcribed Image Text:### Analysis of Variance in Corporate Productivity A random sample of leading companies in South Korea provided the following percentage yields based on assets: - 2.7, 1.7, 4.4, 1.1, 0.1, 3.6, 2.4 - 0.2, 1.7, 1.8, 1.4, 5.4, 1.1 Using a calculator, the variance \( s^2 \approx 2.449 \) for these South Korean companies. Another sample from leading companies in Sweden provided these yields: - 2.1, 3.3, 3.1, 1.6, 3.4, 2.8, 2.3, 3.5, 2.8 The variance is \( s^2 \approx 0.420 \) for these Swedish companies. #### Hypothesis Testing To test if the population variance of percentage yields for South Korean companies is higher than that for Swedish companies, we use a 5% level of significance. This relates to understanding volatility in corporate productivity between South Korea and Sweden. **(a) What is the level of significance?** *Answer:* 5% **State the null and alternate hypotheses:** - \( H_0: \sigma_1^2 = \sigma_2^2 \) - \( H_i: \sigma_1^2 > \sigma_2^2 \) **(b) Calculate the Sample F Statistic:** Find the value of the sample F statistic using two decimal places. This involves the formula for comparing two variances: \[ F = \frac{\text{Variance of South Korean companies}}{\text{Variance of Swedish companies}} \approx \frac{2.449}{0.420} \] **Degrees of Freedom:** - \( df_N \) (numerator): Sample size minus one for South Korean companies. - \( df_D \) (denominator): Sample size minus one for Swedish companies. **What assumptions are made about the original distributions?** Option: The populations follow independent normal distributions. We have random samples from each population. **(c) Find the P-value for the sample test statistic.** Compute this using the F-distribution tables or statistical software. ### Conclusion This test helps determine if there is a statistically significant difference in variance between the
**Math 2250 Unit 4 Post Test Review**

(b) Find the value of the sample F statistic. (Use 2 decimal places.)
\[ \text{F statistic: } \_\_\_\_\_\_\_\_\_\_ \]

**What are the degrees of freedom?**
- \( df_N \): \_\_\_\_\_\_\_
- \( df_D \): \_\_\_\_\_\_\_

**What assumptions are you making about the original distribution?**
- ☐ The populations follow dependent normal distributions. We have random samples from each population.
- ☐ The populations follow independent chi-square distributions. We have random samples from each population.
- ☐ The populations follow independent normal distributions. We have random samples from each population.
- ☐ The populations follow independent normal distributions.

**(c) Find or estimate the \( P \)-value of the sample test statistic.**
- ☐ \( P \)-value > 0.100
- ☐ 0.050 < \( P \)-value < 0.100
- ☐ 0.025 < \( P \)-value < 0.050
- ☐ 0.010 < \( P \)-value < 0.025
- ☐ 0.001 < \( P \)-value < 0.010
- ☐ \( P \)-value < 0.001

**(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis?**
- ☐ At the \( \alpha = 0.05 \) level, we reject the null hypothesis and conclude the data is not statistically significant.
- ☐ At the \( \alpha = 0.05 \) level, we reject the null hypothesis and conclude the data is statistically significant.
- ☐ At the \( \alpha = 0.05 \) level, we fail to reject the null hypothesis and conclude the data are not statistically significant.
- ☐ At the \( \alpha = 0.05 \) level, we fail to reject the null hypothesis and conclude the data are statistically significant.

**(e) Interpret your conclusion in the context of the application.**
- ☐ Fail to reject the null hypothesis, there is sufficient evidence that the variance in percentage yields on assets is greater in the South Korean companies.
- ☐ Reject the null hypothesis, there is insufficient
Transcribed Image Text:**Math 2250 Unit 4 Post Test Review** (b) Find the value of the sample F statistic. (Use 2 decimal places.) \[ \text{F statistic: } \_\_\_\_\_\_\_\_\_\_ \] **What are the degrees of freedom?** - \( df_N \): \_\_\_\_\_\_\_ - \( df_D \): \_\_\_\_\_\_\_ **What assumptions are you making about the original distribution?** - ☐ The populations follow dependent normal distributions. We have random samples from each population. - ☐ The populations follow independent chi-square distributions. We have random samples from each population. - ☐ The populations follow independent normal distributions. We have random samples from each population. - ☐ The populations follow independent normal distributions. **(c) Find or estimate the \( P \)-value of the sample test statistic.** - ☐ \( P \)-value > 0.100 - ☐ 0.050 < \( P \)-value < 0.100 - ☐ 0.025 < \( P \)-value < 0.050 - ☐ 0.010 < \( P \)-value < 0.025 - ☐ 0.001 < \( P \)-value < 0.010 - ☐ \( P \)-value < 0.001 **(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis?** - ☐ At the \( \alpha = 0.05 \) level, we reject the null hypothesis and conclude the data is not statistically significant. - ☐ At the \( \alpha = 0.05 \) level, we reject the null hypothesis and conclude the data is statistically significant. - ☐ At the \( \alpha = 0.05 \) level, we fail to reject the null hypothesis and conclude the data are not statistically significant. - ☐ At the \( \alpha = 0.05 \) level, we fail to reject the null hypothesis and conclude the data are statistically significant. **(e) Interpret your conclusion in the context of the application.** - ☐ Fail to reject the null hypothesis, there is sufficient evidence that the variance in percentage yields on assets is greater in the South Korean companies. - ☐ Reject the null hypothesis, there is insufficient
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