I have the following Hypotheis testing problem.
The statement of the exercise is:
Experiment: Eleven different varieties of barley were considered. Of each variety, half was kiln-dried and the other half was left untreated. Then the two batches of seed were sown in adjacent plots. The experimenter observed that kiln-dried seeds gave, on average, the larger yield of kernels and straw but the quality was generally inferior. The data set “KilnDriedBarley.txt” contains data on the year of the planting, and the value of the crop (in shillings per acre) for both kiln-dried and non-kiln-dried seeds. Seeds sown on adjacent plots are listed in the same row of the file.
Year NonKilnDried KilnDried 1899 140.5 152 1899 152.5 145 1899 158.5 161 1899 204.5 199.5 1899 162 164 1899 142 139.5 1899 168 155 1900 118 117.5 1900 128.5 121 1900 109.5 116.5 1900 120 120.5
(i) “Does kiln-drying barley seeds increase the average value of the crop?” Should we use an independent sample or a paired sample test to answer this question? Defend your choice.
My answer: For this experiment we need to use t test paried sample, because it is assumed that each of the eleven types of seed will have the same condition to growth execect the parameter we want to study, in this case is kiln-dried seed and non-klin dried seeds.
(ii) Use SPSS to create an appropriate graphical display of your data. Your graph should show how the kiln-drying affects crop value. Describe what you can see in the graph.
I need help in this part, because I have no idea how to display my data in SPSS showing my data and the test.
Part (iii) Conduct a statistical hypothesis test for the question in (i) at significance level $\alpha = 0.05.$ Include relevant SPSS output. Formulate a conclusion for the test and cite the appropriate p-value.
This is my output:
My answer: The P-value is .602. We have not enough evidence to reject $H_0$ in favor of $H_a.$ Therefore there isn’t any significance differences between the average value of the crop with kiln-drying barley seeds at a significance level of ($\alpha=5\%$).
1) Are my assumption, and conclusion correct for this experiment? I notice also that both samples has very similar sample std. therefore I assumed homoscedastic (anyway is computed by SPSS).
2) The second problem I have is that I want to use spss, but I can't find an option to graph the t test. (I belive is that what the question ii asked for).
Thank you for your help.