The floor of a room is 6 ft wide and 10 ft long .evaluate the number of tiles required to cover the floor , if the area of each tile is 2 sq ft.( HINT:number of tiles = area of room divide area of one tile .)

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.