When you take a poll, you get only an estimate of the overall approval rating (like the 24 percent approval rating estimate mentioned earlier). When you do that, you are taking a sample from the entire population (e.g., asking one thousand people) and averaging the results to calculate the estimate. This sample mean has a distribution itself, called the sample distribution, which describes the chances of getting each possible approval rating from the sample. You can think of this distribution as the result of plotting the different approval ratings (sample means) obtained from many, many
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