Final answer:
The sampling error measures the discrepancy between a sample statistic and the corresponding population parameter. In the provided scenarios, the sampling errors are -7 for standard deviation and -22.78% for the proportion. To lower the sampling error, increasing the sample size is an effective strategy.
Step-by-step explanation:
The sampling error is the difference between the population parameter and the sample statistic. Here are the calculations for each scenario:
- The sampling error for the mean μ is not provided as the sample mean (μ) is missing in the question.
- For the standard deviation, the sampling error is s - σ, which is 60 - 67 = -7.
- For the proportion, the sampling error is p - P, where P is the sample proportion (615/197) and p is the population proportion (54%). The calculated sample proportion is 615/197 = 3.1218 or 31.22% (assuming 54% is 0.54), hence the sampling error is 31.22% - 54% = -22.78%.
To reduce the sampling error, increasing the sample size is one effective method since the standard error decreases as the sample size increases, according to the formula σ/ √n. The ±3 percent mentioned in the context of a poll represents the margin of error for the poll's findings, which means the true value in the population is expected to fall within 3 percentage points above or below the sample statistic 95% of the times, if the reported confidence level is 95%.