Answer:
It can be concluded that the medicated lotion has an effect on treating skin irritations.
Step-by-step explanation:
In this case we need to determine whether the medicated lotion was effective in treating the skin irritation or not.
The hypothesis can be defined as follows:
<em>H₀</em>: There is no difference between the two proportions, i.e. <em>p</em>₁ - <em>p</em>₂ = 0.
<em>Hₐ</em>: There is a significant difference between the two proportions, i.e. <em>p</em>₁ - <em>p</em>₂ ≠ 0.
The information provided is:
n₁ = 40
n₂ = 40
X₁ = 36
X₂ = 16
Compute the sample proportions and total proportions as follows:

Compute the test statistic value as follows:
The test statistic value is 4.69.
The decision rule is:
The null hypothesis will be rejected if the <em>p</em>-value of the test is less than the significance level.
Compute the <em>p</em>-value as follows:

The <em>p</em>-value of the test is very small.
The null hypothesis will be rejected at any significance level.
Thus, there is a significant difference between the two proportions.
So, it can be concluded that the medicated lotion has an effect on treating skin irritations.