On a new construction site an electrician can install a new light fixture in 20 minutes a project calls for 24 new fixtures to be installed on each of four floors if a work day is 8 hours how many work days will it take to electricians to complete the installations

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?