Excel Instruction Assignment
All home assignments are designed to be done using Microsoft Office Excel. If you buy your textbook, you will find a code in the front inside cover that gives you access to the publishers website to get an online manual of Statistical Computing Using Excel on PC or Mac.
In this home assignment, I recommend you use a combination of Excel and by-hand approaches:
1. To calculate the mean, standard deviation, and median, you can use Excel to get it easily;
2. For t tests, you can use Excel easily as you used to. Just remember that you should compare the variances of two samples first to decide which t test should be used (two-sided with equal variance or two-sided with unequal variance);
3. For Mann-Whitney U tests, please follow the procedures in your text book (as well as in Quiz 10) to do it by hand. Of course, if you have Excel software with the nonparametric tests add-in, you can use it.
4. To generate the Kaplan-Meier curves, you can follow the procedures in your text book (as well as in Quiz 9) to do it by hand. After calculating the survival probabilities at each year (for both groups), you can generate the Kaplan-Meier curve using Excel or by hand. You can scan your drawing and include it in your report.
Excel Assignment - Of note: I made up the data.
Question 1: The efficacies of two drugs, X and Y were evaluated in two groups of mice (Group A, Group B). The outcome was the concentration of the drug in the plasma after giving the mice drugs (through drinking water) for 12 hours. The data were summarized below.
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Group A
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Group B
|
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1
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5
|
|
5
|
8
|
|
5
|
6
|
|
5
|
7
|
|
5
|
8
|
|
6
|
8
|
|
7
|
9
|
|
6
|
16
|
|
10
|
20
|
|
13
|
24
|
Question 1A. At the significance level of 0.05, are the drug concentrations in Group A and Group B different? Using Mann-Whitney U test here.
Question 1B. At the significance level of 0.05, are the drug concentrations in Group A and Group B different? Using the most appropriate t test here.
Question 1C. Are the results ("conclusions") from Question 1A and Question 1B the same? If not, give some possible reasons.
Question 2: The efficacies of two drugs, X and Y were evaluated in two groups of mice (Group C, Group D). The outcome was the concentration of the drug in the plasma after giving the mice drugs (through drinking water) for 24 hours. The data were summarized below.
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Group C
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Group D
|
|
3
|
10
|
|
4
|
7
|
|
6
|
11
|
|
6
|
10
|
|
7
|
9
|
|
5
|
11
|
|
6
|
12
|
|
5
|
14
|
|
8
|
8
|
|
9
|
13
|
Question 2A. At the significance level of 0.05, are the drug concentrations in Group C and Group D different? Using Mann-Whitney U test here.
Question 2B. At the significance level of 0.05, are the drug concentrations in Group C and Group D different? Using the most appropriate t test here.
Question 2C. Are the results ("conclusions") from Question 2A and Question 2B the same? If not, give some possible reasons.
Question 3: A study of patients with Stage I breast cancer is run to assess time to progression to Stage II over an observation period of 15 years. Of interest is whether there is a difference in time to progression between women on two different chemotherapy regimens. Times to progression are measured in years from the time at which chemotherapy regimen was initiated. (Data was from Table 11-26 in your text book.)
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Regimen 1
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Regimen 1
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Regimen 2
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Regimen 2
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|
Progression
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No Progression
|
Progression
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No Progression
|
|
2
|
12
|
9
|
11
|
|
6
|
14
|
4
|
14
|
|
7
|
13
|
7
|
13
|
|
3
|
11
|
|
9
|
|
4
|
15
|
|
14
|
|
10
|
|
13
|
|
8
|
|
6
|
|
6
|
|
9
|
|
9
|
|
7
|
|
12
|
|
|
Q3A. Generate the Kaplan-Meier curves of these two regimens.
Q3B. Based on the Kaplan-Meier curves, estimate the 50% progression-free time for each regimen (i.e the time when the progression probability is 50%). If the progression-free probability is still higher than 50% at the end of the study, the 50% progression-free time >15.
Assignment Files -
https://www.dropbox.com/s/z1s2556pzix5mow/Excel%20Assignment%20Files.rar?dl=0