One of the more popular statistics reported in the media is the president's job approval rating. The approval rating is reported as the proportion of the population who approve of the job that the sitting president is doing and is typically based on a random sample of registered voters where the sample size is the same week to week. Complete parts (a) and (b) below.
a) This proportion tends to fluctuate from week to week. Name some reasons for the fluctuation in the statistic. Select all valid reasons below.
A. The proportion could be changing because the sampling size of the poll is changing.
B. The proportion could be changing because people's attitudes are changing.
C. The proportion could be changing due to a large change in the composition of the population.
D. The proportion could be changing due to sampling error; different people are in the sample.
Answer
Final Answer: The valid reasons for the fluctuation in the president's job approval rating are B, C, and D.
Step 1 ：The question is asking for reasons why the president's job approval rating might fluctuate from week to week. This is a theoretical question and does not require any calculations.
Step 2 ：The reasons for the fluctuation in the statistic could be: A. The proportion could be changing because the sampling size of the poll is changing. However, the question states that the sample size is the same week to week, so this is not a valid reason.
Step 3 ：B. The proportion could be changing because people's attitudes are changing. This is a valid reason. People's opinions can change based on current events, the president's actions, etc.
Step 4 ：C. The proportion could be changing due to a large change in the composition of the population. This is also a valid reason. If the composition of the population changes significantly (e.g., due to immigration, changes in voter registration, etc.), this could affect the approval rating.
Step 5 ：D. The proportion could be changing due to sampling error; different people are in the sample. This is also a valid reason. Even if the sample size is the same, if different people are sampled each week, this could lead to fluctuations in the approval rating.
Step 6 ：Final Answer: The valid reasons for the fluctuation in the president's job approval rating are B, C, and D.
