A devign engineer wants to construct a sample mon chart for cortroling the service life of a halogen headlamp his company standard acviation of 20 hours. On three recent production tatches he lested service life on random samples of four head amps. with these results. What are the x-har clust useer anal lawer control i mils?\table[[Sample,Senice Life itherwis)],[1,405,500,505,500],[2,525,315,505,515],[3,470,480,460,470]]450 and 440C.900 and 475E.552 and 544B.507 and 483D.523 and 515