Final answer:
The sampling error of ±3 percent represents the estimated range that the true value of a poll is likely to be within. To lower this margin of error, increasing the sample size is an effective solution. Larger samples typically yield more reliable and predictive results.
Step-by-step explanation:
The sampling error reported by Yankelovich Partners, Inc. is ±3 percent. This figure represents the estimated range within which the true value of a poll result is likely to lie. For instance, if a poll result shows that 50% of the population supports a certain policy, the sampling error of ±3 percent indicates that the true support level could be as low as 47% or as high as 53%.
To lower the sampling error, one effective method is to increase the sample size. A larger sample tends to lead to a smaller sampling error because it decreases the effect of random chance in the poll results, making the poll more reliable and its findings more predictive of the total population's opinions or behaviors.