Example 1
trout make up 20.4% of the fish. the estimate is correct within 19 times out of 20
margin of error: confidence interval:
Example 2
in 2009, 234 trout caught out of total catch of 911. in 2012, 141 trout caught out of catch 689. a) determine the percent of lake trout caught for each year b) determine margin of error each year. assume 95% confidence level c) determine the confidence interval for each year d) do the 2 confidence intervals overlap?
Answer a
2009: 2012:
Answer b
2009: = 0.028 2012:
Answer c
2009: 2012:
Answer d
yes. they do. Because there is overlap in the confidence interval, we can NEVER be sure if the population decreased