A scientist working for a large agriculture company isinterested in comparing the effect of various feed additives on thegrowth of chickens. Chickens were given feed supplemented witheither soy, cornmeal, whey, linseed, or cricket flour. Theircurrent diet is feed with a soy supplement. After 12 weeks on thediet, each chicken was weighed and the value (in grams) wasrecorded in the table below. Analyze the data to determine if thereis a difference in chicken weight between the different additivesand if so, which supplement is the most effective.
Supplement Type |
Soy | Cornmeal | Whey | Linseed | Cricket |
43.5 | 15.2 | 50.4 | 115.9 | 17.1 |
60.1 | 23.4 | 63.2 | 75.5 | 21.5 |
45.1 | 19.7 | 91.3 | 113.4 | 13.5 |
47.4 | 13.4 | 36.3 | 53.4 | 13.1 |
18.1 | 16.9 | 87.4 | 103.5 | 25.3 |
29.1 | 11.4 | 27.7 | 136.6 | 32.3 |
a. Was a pretest performed? If so, fill in the values in thetable.
Test type | |
H0 | |
HA | |
Crit/Calc or exact p-value | |
If not, explain why:
b. What was the conclusion of your pre-test? Do you need totransform your data? If so, fill in the transformation you used andyour new critical/calculated value or new p-value.
Conclusion:
Transformation | |
New Calc/Crit or p-value | |
c. What are the null and alternative hypotheses for your maintest?
d. Complete the ANOVA table:
V ariance source | df | SS | MS | F | P-value |
Among | | | | | |
Within | | | | | |
Total | | | | | |
e. What conclusions can you draw? Do you need to do any post-hoctesting?
f. If you need to do post-hoc testing, fill in the blank cellsin the table below with: which post- hoc test you chose and thep-values for each pair of comparisons. Note: the format of thetable is generic and saves space; it is not meant to imply aspecific test.
Post-hoc Test: | |
| Soy | Cornmeal | Whey | Linseed |
Cricket | | | | |
Linseed | | | | |
Whey | | | | |
Cornmeal | | | | |
g. Plot your data. Based on the results of your ANOVA andpost-hoc testing, what is your biological conclusion? Use the plotto be as specific as possible.
