Do employees of computer manufacturing perform better at work with music playing. the music was turned on during theworking hours of a business with 45 employees. their productivity level averaged 5.2 with a standard deviation of 2.4. ona different day the music was turned off and there were 40 workers. the workers' productivity level averaged 4.8 with a standard deviation of 1.2. what can we conclude at 90% level of confidence (compare ci for music on and music off)? a. employees perform better at work with music playing. b. employees performance doesn