Problem 4. Lin, sutton, and Qurashi (1979) compared microbiological and hydroxyl

Question

Problem 4. Lin, sutton, and Qurashi (1979) compared microbiological and hydroxylamine methods for the analysis of ampicillin dosages. In one series of experiments, pairs of tablets were analyzed by the two methods. The data in the following table give the percentages of claimed amount of ampicillin found by the two methods in several pairs of tablets. Anlyze the data to determine if there is a systematic difference between the two methods. Microbiological Method Hydroxylamine Method 97.2 97.2 105.8 97.8 99.5 96.2 100.0 101.8 93.8 88.0 79.2 74.0 72.0 75.0 72.0 67.5 69.5 65.8 20.5 21.2 95.2 94.8 90.8 95.8 98.0 96.2 99.0 96.2 100.2 91.0

Explanation / Answer

R code:

micro=c(97.2,105.8,99.5,100.0,93.8,79.2,72.0,72.0,69.5,20.5,95.2,90.8,96.2,96.2,91.0)
hydro=c(97.2,97.8,96.2,101.8,88.0,74.0,75.0,67.5,65.8,21.2,94.8,95.8,98.0,99.0,100.2)
diff = micro - hydro
t_test = t.test(diff)
t_test

R code output:

   One Sample t-test

data: diff
t = 0.368, df = 14, p-value = 0.7184
alternative hypothesis: true mean is not equal to 0
95 percent confidence interval:
-2.124433 3.004433
sample estimates:
mean of x
0.44

Conclusion:

As the p-value of the test is 0.7184, which is significantly higher than any common level of significance e.g. 5% (0.05) and 95% confidence interval includes zero, we cannot reject the null hypothesis that the difference between two methods is zero. So, we conclude that there is NO systematic difference between the two methods.

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.