In: Statistics and Probability
You are testing a treatment for a new virus. Effectiveness is judged by the percent reduction in symptoms after two weeks.It is known that if left untreated, symptoms will reduce on their own by 0.185 (18.5%) with a standard deviation of 0.123. Three trials were run simultaneously.Trial 1 involved giving the participants a sugar pill. Patients in Trial 2 were given Agent A. Patients in Trial 3 were given Agent B. Results showing the amount of symptom reduction for the various trials are summarized in the table to the left. Note that this is NOT a paired t-test.Patient 1 just means the first patient to be given the treatment in each trial. Patient 1 is a different person in each trial.
1) At the 80%, 90% and 95% confidence levels (alpha = 0.2, 0.1 and 0.05) compare Agent A, Agent B and the Sugar Pill results to the population symptom reduction. Use a one-tail hypothesis test.
Percent Reduction in Symptoms after 2 weeks | ||||||
Sugar Pill | Agent A | Agent B | ||||
Person 1 | 0.15 | 0.8 | 0.25 | |||
Person 2 | 0.18 | 0.02 | 0.31 | |||
Person 3 | 0.05 | 0.18 | 0.44 | |||
Person 4 | 0.35 | 0.9 | 0.6 | |||
Person 5 | 0.22 | 0.12 | 0.08 | |||
Person 6 | 0.22 | 0.11 | 0.12 | |||
Person 7 | 0.2 | 0.33 | 0.33 | |||
Person 8 | 0.15 | 1 | 0.5 | |||
Person 9 | 0.45 | 0.07 | 0.31 | |||
Person 10 | 0.1 | 0.15 | 0.18 | |||
Person 11 | 0.29 | 0.08 | 0.2 | |||
Person 12 | 0.08 | 0.02 | 0.33 | |||
Person 13 | 0.3 | 0.16 | 0.02 | |||
Person 14 | 0.21 | 0.09 | 0.17 | |||
Person 15 | 0.13 | 0.77 | 0.38 | |||
Person 16 | 0.4 | 0.85 | 0.46 | |||
Person 17 | 0.31 | 0.03 | 0.23 | |||
Person 18 | 0.02 | 0.06 | 0.31 | |||
Person 19 | 0.09 | 0.18 | 0.28 | |||
Person 20 | 0.17 | 0.22 | 0.09 | |||
average | 0.204 | 0.307 | 0.280 | |||
std dev | 0.117 | 0.340 | 0.150 | |||
VAR | 0.0136 | 0.1159 | 0.0225 | |||
Q1 | Ho: muX <= 0.185 (where X = Sugar Pill, Agent A or Agent B) | |||||||||
Sugar Pill vs. Populatoin | Agent A vs Population | Agent B vs Population | ||||||||
Alpha | Test stat | Critical value | Conclusion | Test stat | Critical value | Conclusion | Test stat | Critical value | Conclusion | |
0.2 | ||||||||||
0.1 | ||||||||||
0.05 |
Ans ) for sugar pill vs population
we have
t Test for Hypothesis of the Mean | |
Data | |
Null Hypothesis m= | 0.185 |
Level of Significance | 0.2 |
Sample Size | 20 |
Sample Mean | 0.2035 |
Sample Standard Deviation | 0.116631448 |
Intermediate Calculations | |
Standard Error of the Mean | 0.0261 |
Degrees of Freedom | 19 |
t Test Statistic | 0.7094 |
Upper-Tail Test | |
Upper Critical Value | 0.8610 |
p-Value | 0.2434 |
Do not reject the null hypothesis |
for Agent A vs population
t Test for Hypothesis of the Mean | |
Data | |
Null Hypothesis m= | 0.185 |
Level of Significance | 0.2 |
Sample Size | 20 |
Sample Mean | 0.307 |
Sample Standard Deviation | 0.340419246 |
Intermediate Calculations | |
Standard Error of the Mean | 0.0761 |
Degrees of Freedom | 19 |
t Test Statistic | 1.6027 |
Upper-Tail Test | |
Upper Critical Value | 0.8610 |
p-Value | 0.0627 |
Reject the null hypothesis |
for Agent B vs population
we have
t Test for Hypothesis of the Mean | |
Data | |
Null Hypothesis m= | 0.185 |
Level of Significance | 0.2 |
Sample Size | 20 |
Sample Mean | 0.2795 |
Sample Standard Deviation | 0.150034207 |
Intermediate Calculations | |
Standard Error of the Mean | 0.0335 |
Degrees of Freedom | 19 |
t Test Statistic | 2.8168 |
Upper-Tail Test | |
Upper Critical Value | 0.8610 |
p-Value | 0.0055 |
Reject the null hypothesis |
Sugar Pill vs. Populatoin | Agent A vs Population | Agent B vs population | |||||||
Alpha | Test stat | Critical value | Conclusion | Test stat | Critical value | Conclusion | Test stat | Critical value | Conclusion |
0.2 | 0.7094 | 0.861 | Fail to Reject Ho | 1.6027 | 0.861 | Reject Ho | 2.8168 | 0.861 | Reject Ho |
0.1 | 0.7094 | 1.3277 | Fail to Reject Ho | 1.6027 | 1.3277 | Reject Ho | 2.8168 | 1.3277 | Reject Ho |
0.05 | 0.7094 | 1.7291 | Fail to Reject Ho | 1.6027 | 1.7291 | Fail to Reject Ho | 2.8168 | 1.7291 | Reject Ho |