Question

Write down the R solutions of the following questions.

Two types of medication for COVID-19 are being tested to determine if there is a difference in the percentage of adult patient reactions. 20 out of a random sample of 200 adults given Medication_A still had COVID-19 30 minutes after taking the medication. 12 out of another random sample of 200 adults given Medication_B still had COVID-19 30 minutes after taking the medication. Test the equality of proportions at a 1% level of significance.

Answer 1

$x_a=20$

$n_a=200$

$x_b=12$

$n_b=200$

$\alpha=0.01$

$H0:P_a=P_b$

$Ha:P_a\ne P_b$

The following R code can be used (with continuity correction).

> prop.test(x=c(20,12),n=c(200,200),conf.level = .99)

The results are;

	2-sample test for equality of proportions with continuity correction

data:  c(20, 12) out of c(200, 200)
X-squared = 1.6644, df = 1, p-value = 0.197
alternative hypothesis: two.sided
99 percent confidence interval:
 -0.03469035  0.11469035
sample estimates:
prop 1 prop 2 
  0.10   0.06 

The p-value is 0.197 which is greater than 0.01. Thus, we fail to reject the null hypothesis and conclude that that there is no significant difference between the two proportions.