4 Is this andbservational study or anexperiment? Justifyyour answer. This is on observational study. The researchers are not assigning the shifts Nurse Gilbert worked or did not work. So what did the researchers find when they analyzed the 1,641 eight-hour shifts? They foundthat Glbat workedon 257 of theshifts andshedidnot workon1,384of them Theyalso foundthat apatient diedduring 74of theshifts, andnodeathoccurredontheother 1,567 shifts