A randomized controlled trial is run to evaluate the effectiveness of a new drug for asthma in children. A
total of 250 children are randomized to either the new drug or placebo (125 per group). There are 63
boys assigned to the new drug group and 58 assigned to the placebo. Is there a statistically significant
difference in the proportion of the boys assigned to the treatments? Apply the appropriate test at a 5%
level of significance (1) Critical value = +/-
(2) computed statistics
(3) Based on comparing the
computed statistics to the critical value which of the following is (are) true? (a) There is significant
evidence, alpha =0.05, that there is a difference in the proportions of boys assigned to the treatments (b)
A clinical trial is conducted to investigate the effectiveness of an experimental drug in reducing preterm
delivery to a drug consigned standard care and to placebo. Pregnant women are enrolled and randomly
assigned to receive either the experimental drug, the standard drug or placebo. Women are followed
through delivery and classified as delivery preterm (>37 weeks) or not The data are shown below.
Is there a statistically significant difference in the proportions of women delivery preterm among the
THREE treatments groups? Apply the test of 5% level of significance.
3. computed value =
4. based on comparing the computed chi square with the critical values for the Chi square which of the
following is (are) true?