Homework SourseChiSqr Independence Test Is vaccine effective in treating MN
Chi-Sqr Independence Test. Is vaccine effective in treating MN Strain of HIV? alpha =.05. New, effective AIDS vaccines are now being developed using the process of \"sieving\" (i.e., sifting out infections with some strains of HIV). Harvard School of Public Health Statistician Peter Gilbert demonstrated how to test the efficacy of an HIV vaccine in Chance (Fall 2000). As an example. Gilbert reported the results of VaxGen\'s preliminary HIV vaccine trial using the 2 Times 2 table below. The vaccine was designed to eliminate a particular strain of the virus, called the \"MN strain.\" The trial consisted of 7 AIDS patients vaccinated with the new drug and 31 AIDS patients who were treated with a placebo (no vaccination). The table (saved in the HIV1 file) shows the number of patients who tested positive and negative for the MN strain in the trial follow-up period.
Solution
Ho: there is no change in vaccine effect in treating MN strain of HIV, Against H1:there is change in vaccine effect in treating MN strain of HIV.
Chi-square calculated value is 4.407 and table value at .5 is 3.841, chisquare cal > chisquare tab, so we reject Ho. Therefore, there is change in vaccine effect in treating MN strain of HIV.
| Oi | Ei | (Oi-Ei)2/Ei |
| 22 | 19.58 | .299 |
| 9 | 11.42 | .513 |
| 2 | 4.42 | 1.325 |
| 5 | 2.58 | 2.27 |
| 38 | 38 | 4.407 |
