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.
5.91 | 7.10 | 5.70 | 5.91 | 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 s2 ≈ 0.404.
Another random sample of years for a second plot gave the following
annual wheat production (in pounds).
7.38 | 6.68 | 7.59 | 6.75 | 7.22 | 5.58 | 5.47 | 5.86 |
Use a calculator to verify that the sample variance for this
plot is s2 ≈ 0.694.
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.)
(c) Find or estimate the P-value of the sample test
statistic. (Use 4 decimal places.)
p-value > 0.2000.100 < p-value < 0.200 0.050 < p-value < 0.1000.020 < p-value < 0.0500.002 < p-value < 0.020p-value < 0.002
What are the degrees of freedom?
dfN:
dfD:
a)level of significance =0.05
null hypothesis: | σ21 | = | σ22 | ||
Alternate Hypothesis: | σ21 | < | σ22 |
b)
Test statistic =s22/s12 = | 1.72 |
c)
p-value > 0.20
dfN: 7
dfD: 10
Two plots at Rothamsted Experimental Station were studied for production of wheat straw. For a random...
6)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. 6.68 5.84 7.03 6.89 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 s2 ≈ 0.335. Another random sample of years for a second plot gave the following annual wheat production (in pounds). 7.59 6.12 6.54 7.80...
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. 6.96 7.10 5.84 5.91 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 s2 ≈ 0.384. Another random sample of years for a second plot gave the following annual wheat production (in pounds). 5.91 5.91 5.91 5.91...
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. 6.33 5.84 5.98 5.77 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 s2 ≈ 0.340. Another random sample of years for a second plot gave the following annual wheat production (in pounds). 5.91 5.77 6.47 6.75...
Rothamsted Experimental Station (England) has studied wheat production since 1852. Each year, many small plots of equal size but different soil/fertilizer conditions are planted with wheat. At the end of the growing season, the yield (in pounds) of the wheat on the plot is measured. For a random sample of years, one plot gave the following annual wheat production (in pounds). 4.29 3.90 3.99 3.87 4.29 3.79 4.09 4.42 3.89 3.87 4.12 3.09 4.86 2.90 5.01 3.39 Use a calculator...
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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. 4.2 5.5 3.6 3.9 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 4.5 Use a calculator to verify that the sample variance is s2 ≈...
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