Explain the difference between an independent and dependent sa...

Question

Explain the difference between an independent and dependent sample.

Accepted Answer

Hello. In this video, we want to determine which scenario best describes a situation that requires a hypothesis test for dependent proportions. Now, as we're looking through the problems, we want to keep the word dependent paired in the back of our minds. Now, the reason for this being is that as we're reading through each of the options, we want to determine if the two variables and the options affect one another. So, for example, A has a direct impact on B. So, let's go ahead and take a look at the prompt given to us in option A. A says that we are going to compare the proportion of students who pass a math final at a school A versus the proportion of students who pass the same final at school B. Now if we are taking a look at this, we are talking about the results from two different schools, but if a student passes at one school, that doesn't necessarily mean that another student is going to pass at the secondary school. So with that being said, both of the variables in option A are going to be independent. They do not affect one another, so option A is not going to be the solution. Now let's take a look at option B. Option B says that we are comparing the proportion of voters who approve the new policy among a randomly selected sample of men versus a randomly selected sample of women. Now, similar to a, if a man supports. A vote for a new policy that doesn't necessarily mean that a woman will support the policy at the same time. And so what this means is that this is going to be another case where we have independent variables. One variable does not affect the other, so option B is not going to be a solution. Now option C says that we are comparing the proportions of patients with a successful outcome before a new drug intervention to the proportion of patients with the same successful outcome after the intervention. Now here we have two different groups of patients, a group of patients that are successful after the treatment and another that is not successful. But the common thing between them is that they are both trying the same drug and the drug is going to be affecting the patients in different ways. So the drug relates the two groups together, therefore, the group of people and the drug are going to be dependent on each other. So option C is going to be a solution. And now if we take a look at option D. We are comparing the proportion of defective items produced on assembly line 1 to the proportion of defective items on assembly line 2. Now if we have items on one assembly line, if one is defective, that doesn't necessarily mean that another item will be defective on the opposite assembly line. So for option D, both assembly lines are going to be independent variables, and option D is not going to be a solution. So the only valid solution is going to be option C. It is dependent because the outcome depends on the drug's effect on the individuals. So, I hope this video helps you in understanding how to approach this problem, and we will go ahead and see you all in the next video.

Explain the difference between an independent and dependent sample.

Key Concepts

Independent Samples

Dependent Samples

Implications for Statistical Analysis

Watch next