Final answer:
A sampling error of ±3 percent means the true value in the population likely falls within 3 percentage points above or below the poll's reported value. Lowering the sampling error generally involves increasing the sample size and ensuring a random and representative sample.
Step-by-step explanation:
A sampling error of ±3 percent in a public opinion poll indicates the range within which the true value in the broader population is likely to fall. For instance, if a poll shows a candidate has 50 percent support with a ±3 percent sampling error, the candidate's actual support could be between 47 percent and 53 percent. Polls aim to be a miniature representation of the whole population, and the margin of error communicates the level of confidence in the poll's accuracy. Smaller margins of error are generally better because they provide a more precise estimate of the population's opinions or behaviors.
To lower the sampling error, pollsters can increase the sample size, ensuring the sample is random and representative of the whole population. A larger sample size tends to reduce the chance of error since it minimizes the impact of outliers and ensures that the diversity of the entire population is better reflected in the sample. Therefore, a poll with a ±3 percent margin of error is considered relatively reliable, assuming it is based on an adequate sample size and the polling methodology is sound.