Noise Levels in Hospitals The mean noise level of 20 areas designated as casualty doors was 63.1 dBA, and the standard deviation is 4.1 dBA. The mean noise level for 24 areas designated as operating theaters was 56.3 dBA, and the standard deviation was 7.5 dBA. At a _ 0.05, can it be concluded that there is a difference in the means?

STAT 2004 Week 2 Lecture 5 Fri. 01/27/17 Observational study: data analysis where researcher does not interfere with data outcomes Experiment: researcher directly interferes with data outcomes y imposing treatments and controls Observational An example of an observational study would be a survey: did you get a flu shot Observational studies help establish correlation Experiment...