A rаndоm sаmple оf 144 оbservаtions has a mean of 20, a median of 21, and a mode of 22. The population standard deviation is known to equal 4.8. The 95.44% confidence interval for the population mean is 19.2 to _____________. Refer to the following formula and table. σ x = σ n z = x - μ σ x Standard Error = σ n Margin of Error = z α / 2 * σ n Confidence Interval = x ± z α / 2 * σ n z dsistribution table from 0.0 to 2.49.jpg