Experts use statistics to understand large and complex sets of data. Statistics are also helpful with surveys, which legislators use to affect policy. Knowing how statistics work is important for fully understanding news reports.
Large sets of data can be complex, and understanding what the data means requires advanced analytical tools. Statistics is a set of tools than can inform experts dealing with complex information. Many medical studies rely on the p-value, which helps determine if a statistically significant effect is present at the end of a trial. Relatively new tools, like Bayesian analysis, can provide even better information.
While politicians are often accused of implementing policy based on polling data, public opinion polls can help politicians determine what citizens want; however, public opinion polls can also be used deceptively to showcase inaccurate results. So-called "push polls" use questions that may skew the results.
Understanding statistics helps people determine the meaning of statistics in the news and other fields. Knowing that one outlier can skew averages is important, and understanding the margin of error is essential when dealing with relatively small effects. News organizations and other entities have been known to release deceptive data; learning how data can be misused is essential for determining what to believe.