True or false?

"When σ is unknown, to get a certain margin of error, one should use an estimate of σ that is considered to be at least as large as the true σ. This will provide a conservative sample size to be on the safe side."

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.