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2. [0.56/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 10.4.006. Two plots at Rothamsted Experimental Station were studied for production of wheat straw. For a random sample of years, the annual wheat straw production (in pounds) from one plot was as follows. 7.17 7.17 5.70 6.26 7.31 7.18 7.06 5.79 6.24 5.91 6.14 Use a calculator to verify that, for this plot, the sample variance is s* 0.406. Another random sample of years for a second plot gave the following annual wheat production (in pounds). 7.10 7.59 5.84 7.03 7.22 5.58 5.47 5.86 Use a calculator to verify that the sample variance for this plot is s' * 0.727. Test the claim that there is a difference (either way) in the population variance of wheat straw production for these two plots. Use a 5% level of signifcance. (a) What is the level of significance? State the null and alternate hypotheses. (b) Find the value of the sample F statistic. (Use 2 decimal places.) What are the degrees of freedom?3. [0.56/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 10.4.007. MY NOTES ASK YOUR TEACHER PRACTICE An economist wonders if corporate productivity in some countries is more volatile than in other countries. One measure of a company's productivity is annual percentage yield based on total company assets. A random sample of leading companies in France gave the following percentage yields based on assets. 4.7 5.1 3.4 3.4 2.7 3.5 2.8 4.4 5.7 3.4 4.1 6.8 2.9 3.2 7.2 6.5 5.0 3.3 2.8 2.5 45 Use a calculator to verify that the sample variance is s' # 2.005 for this sample of French companies. Another random sample of leading companies in Germany gave the following percentage yields based on assets. 3.3 3.4 3.2 4.5 5.6 5.5 5.0 5.4 3.2 3.5 3.7 2.6 2.8 3.0 3.0 2.2 4.7 3.2 Use a calculator to verify that s? * 1.134 for this sample of German companies. Test the claim that there is a difference (either way) in the population variance of percentage yields for leading companies in France and Germany. Use a 5% level of significance. How could your test conclusion relate to the economist's question regarding volatility (data spread) of corporate productivity of large companies in France compared with companies in Germany? (a) What is the level of significance? State the null and alternate hypotheses. (b) Find the value of the sample F statistic. (Use 2 decimal places.) What are the degrees of freedom?4. [0.56/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 10.4.008. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A random sample of leading companies in South Korea gave the following percentage yields based on assets. 2.4 1.6 4.7 7 1.1 0.3 3.6 2.4 0.2 1.7 1.8 1.4 5.4 1.1 Use a calculator to verify that s" # 2.492 for these South Korean companies. Another random sample of leading companies in Sweden gave the following percentage yields based on assets. 2.7 3.3 3.7 1.6 3.7 2.8 2.3 3.5 2.8 Use a calculator to verify that s' * 0.487 for these Swedish companies. Test the cl entage yields on assets for South Korean in Sweden. Use a 5% level of significance. How could your test compared with those in Sweden? (@) What is the level of significance? State the null and alternate hypotheses. (b) Find the value of the sample F statistic. (Use 2 decimal places.) What are the degrees of freedom? dFN df5. [0.56/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 10.4.009. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER You don't need to be rich to buy a few shares in a mutual fund. The question is, how reliable are mutual funds as investments? This depends on the type of fund you buy. The following data are based on information taken from a mutual fund guide available in most libraries. A random sample of percentage annual returns for mutual funds holding stocks in aggressive-growth small companies is shown below. -1.7 14.2 41.5 17.3 -16.6 4.4 32.6 -7.3 16.2 2.8 34.3 -10.6 8.4 -7.0 -2.3 -18.5 25.0 -9.8 -7.8 -24.6 22.8 Use a calculator to verify that s' * 347.943 for the sample of aggressive-growth small company funds. Another random sample of percenta ual returns for mutual funds holding value (i.e., market underpriced) stocks in large companies is shown below. 16.1 0.6 7.4 -1.1 -3.9 19.4 -2.5 15.9 3 6 22.1 3.4 -0.5 - 14.6 5 18.0 21.0 0.2 -1.6 Use a calculator to verify that s?* 136.655 for value stocks in large companies. Test the claim that the population variance for mutual funds holding aggressive-growth in small companies is larger than the population variance for mutual funds holding value stocks in large companies. Use a 5% level of significance. How could your test conclusion relate to the question of reliability of returns for each type of mutual fund? (a) what is the level of significance? State the null and alternate hypotheses. OH,:0,2 =027; H,102>622 (b) Find the value of the sample F statistic. (Use 2 decimal places.) What are the degrees of freedom?6. [0.56/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 10.4.010. MY NOTES ASK YOU How reliable are mutual funds that invest in bonds? This depends on the bond fund you buy. A random sample of annual percentage returns for mutual funds holding short-term U.S. government bonds is shown below. 4.6 4:4 1.9 9.7 -0.9 4.1 10.5 4.2 3.5 3.9 9.8 -1.2 7.3 Use a calculator to verify that s" * 14.014 for the preceding data A random sample of annual percentage returns for mutual funds holding intermediate-term corporate bonds is shown below. -0.7 3.5 20.8 7.8 -0.1 18.8 -3.4 10.5 8.0 -0.9 2.6 14.9 -6.5 8.2 18.8 14.2 Use a calculator to verify that s" * 72.758 for returns from mutual funds holding intermediate-term corporate bonds. Use a = 5% to test the claim that the population variance for annual percentage returns of mutual funds holding short-term government bonds is different from the population variance for mutual funds holding intermediate-term corporate bonds. How could your test conclusion relate to the question of reliability of returns for each type of mutual fund? (a) What is the level of significance? State the null and alternate hypotheses. (b) Find the value of the sample F statistic. (Use 2 decimal places.) What are the degrees of freedom? dry7. [0.45/1 Points] DETAILS PREVIOUS ANSWERS BBUNDERSTAT12 10.4.012. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A new thermostat has been engineered for the frozen food cases in large supermarkets. Both the old and new thermostats hold temperatures at an average of 250F. However, it is hoped that the new thermostat might be more dependable in the sense that it will hold temperatures closer to 25F. One frozen food case was equipped with the new thermostat, and a random sample of 26 temperature readings gave a sample variance of 4.2. Another similar frozen food case was equipped with the old thermostat, and a random sample of 19 temperature readings gave a sample variance of 12.6. Test the claim that the population variance of the old thermostat temperature readings is larger than that for the new thermostat. Use a 5% level of significance. How could your test conclusion relate to the question regarding the dependability of the temperature readings? (Let population 1 refer to data from the old thermostat.) (a) what is the level of significance? State the null and alternate hypotheses. O Ho: 612 = 027: H1:012 #623 (b) Find the value of the sample F statistic. (Round your answer to two decimal places.) What are the degrees of freedom? df= dip = What assumptions are you making about the original distribution? O The populations follow independent normal distributions. O The populations follow independent chi-square distributions. We have random samples from each population. O The populations follow dependent normal distributions. We have random samples from each population. The populations follow independe ormal distributions. We have random samples from each population. c) Find or estimate the P-value of the statistic. (Round your answer to four decimal places.) p-value > 0.100 0.050