Question

In clinical trials of a newly developed cold medicine, it was found that 45 out of 200 individuals that took the new medicine (Group 1) experienced an upset stomach as a side effect and 33 out of 150 individuals that took a placebo (Group 2) experienced an upset stomach. Test to see if the new drug produced a significantly higher proportion of individuals experiencing upset stomach. Use a 0.01 level of significance. Select the correct alternative hypothesis and decision.
a. H: Pi≠P2; Do not reject the null hypothesis.
b. H1: p1>P2; Do not reject the null hypothesis.
c. H: Pi > p2; Reject the null hypothesis.
d. H1: p. e.) Hi: p1≠P2; Reject the null hypothesis.
f. H: P1

Answer 1

Answer:

Step-by-step explanation:

Group 1 Information:

sample size  :  n₁  =  200

individuals with stomach as a side effect  x₁  = 45

p₁ =  45 / 200   p₁ = 0,225   then  q₁  =  1  -  p₁   q₁ =  0,775

Group 2 Information:

sample size  :  n₂ =  150

individuals with stomach as a side effect  x₂  = 33

p₂  =  33/150  p₂ = 0,22   q₂   =  0,78

Hypothesis Test:

Null Hypothesis:                             H₀         p₁   =  p₂

Alternative Hypothesis                  Hₐ         p₁   >   p₂

The alternative hypothesis indicates that the test is a one-tail test  to the right

Significance level is   α = 0,01   ( confidence interval  99%)

From  z-table we get z(c) for that α     z(c) =  2,32

To calculate z(s)

z(s)  =  (  p₁  -  p₂ ) / EED

EED =  √ ( p₁*q₁)/n₁  +  ( p₂*q₂)/n₂

EED =  √ ( 0,225*0,775)/200   + (0,22*0,78)/150

EED =  √ 0,0008718  + 0,001144

EED =  0,045

z(s)  =  ( 0,225  -  0,22 ) / 0,045

z(s)  =  0,005 / 0,045

z(s)  =  0,11

Comparing z(s)  and  z(c)

z(s)  <  z(c)        0.11 < 2.32

Then z(s) is in the acceptance region. We accept  H₀ . We don´t have evidence to support differences between the two groups.