In: Statistics and Probability
Question 1: A researcher is testing 4 different blood coagulation drugs. The drugs are labeled A,B,C and D. He is interested in how the drugs affect the blood coagulation rates of mice. The coagulation rate is the time in seconds that it takes for a cut to stop bleeding. He has 16 mice available for the experiment, so he will use 4 on each drug, randomized.
A B C D
62 63 68 56
60 67 66 62
63 71 71 60
59 64 61
64
a. Perform CRD (completely randomized design) manually as we did in the lectures. You need to write the STEPS clearly.
b. Watch the video on, CRD & CRBD on how to perform EXCEL calculation for CRD
c. Use the attached EXCEL sheet to perform the same calculation.
PART 2: Three different washing solutions are being compared to study their effectiveness in retarding bacteria growth in 5-gallon milk containers. The analysis is done in a laboratory, and only three trials can be run on any day. Because days could represent a potential source of variability, the experimenter decides to use a randomized block design. Observations are taken for four days, and the data are shown here.
Days |
||||
Solution |
1 |
2 |
3 |
4 |
1 |
13 |
22 |
18 |
39 |
2 |
16 |
24 |
17 |
44 |
3 |
5 |
4 |
1 |
22 |
a. Watch the video on, CRD & CRBD on how to perform EXCEL calculation
b. Use the attached EXCEL sheet to perform the calculation for CRBD
PART 3: Explosive manufacturer conducts an experiment to study the explosive force of 4 different mixtures. It is planned to run five replicates (5 runs with each mixture).. The experiment is conducted outdoors which meant only 4 runs cam be made in a given day. Because conditions on each day and can affect the test results, a randomized block design is used, blocking against each day.
Data on next sheet
Mixture Day1 Day2 Day3 Day4 Day5
1 72 68 74 71 67
2 73 67 75 72 70
3 75 68 78 73 68
4 73 71 75 75 69
Determine if mixture affects explosive force.
a. Watch the video on, CRD & CRBD on how to perform EXCEL calculation
b. Use the attached EXCEL sheet to perform the calculation for CRBD
Question 1: PART 1:
c.
Anova: Single Factor | ||||||
SUMMARY | ||||||
Groups | Count | Sum | Average | Variance | ||
A | 5 | 308 | 61.6 | 4.3 | ||
B | 4 | 265 | 66.25 | 12.91667 | ||
C | 3 | 205 | 68.33333 | 6.333333 | ||
D | 4 | 239 | 59.75 | 6.916667 | ||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Between Groups | 174.5708 | 3 | 58.19028 | 7.813689 | 0.003721 | 3.490295 |
Within Groups | 89.36667 | 12 | 7.447222 | |||
Total | 263.9375 | 15 |
PART 2:
Anova: Two-Factor Without Replication | ||||||
SUMMARY | Count | Sum | Average | Variance | ||
1 | 4 | 92 | 23 | 127.3333 | ||
2 | 4 | 101 | 25.25 | 168.9167 | ||
3 | 4 | 32 | 8 | 90 | ||
1 | 3 | 34 | 11.33333 | 32.33333 | ||
2 | 3 | 50 | 16.66667 | 121.3333 | ||
3 | 3 | 36 | 12 | 91 | ||
4 | 3 | 105 | 35 | 133 | ||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Solution | 703.5 | 2 | 351.75 | 40.71704 | 0.000323 | 5.143253 |
Days | 1106.917 | 3 | 368.9722 | 42.71061 | 0.000192 | 4.757063 |
Error | 51.83333 | 6 | 8.638889 | |||
Total | 1862.25 | 11 |
Since p-value corresponding Solution<0.05, so effects of three different washing solutions are not all equal.
PART 3:
Anova: Two-Factor Without Replication | ||||||
SUMMARY | Count | Sum | Average | Variance | ||
1 | 5 | 352 | 70.4 | 8.3 | ||
2 | 5 | 357 | 71.4 | 9.3 | ||
3 | 5 | 362 | 72.4 | 19.3 | ||
4 | 5 | 363 | 72.6 | 6.8 | ||
Day 1 | 4 | 293 | 73.25 | 1.583333 | ||
Day 2 | 4 | 274 | 68.5 | 3 | ||
Day 3 | 4 | 302 | 75.5 | 3 | ||
Day 4 | 4 | 291 | 72.75 | 2.916667 | ||
Day 5 | 4 | 274 | 68.5 | 1.666667 | ||
ANOVA | ||||||
Source of Variation | SS | df | MS | F | P-value | F crit |
Mixture | 15.4 | 3 | 5.133333 | 2.919431 | 0.077554 | 3.490295 |
Day | 153.7 | 4 | 38.425 | 21.85308 | 1.94E-05 | 3.259167 |
Error | 21.1 | 12 | 1.758333 | |||
Total | 190.2 | 19 |
Since p-value=0.077554>0.05 so force of 4 different mixtures are insignificantly different at 5% level of significance.