X= 45, you would place 15 into y's place, which would give you x-15= 30... then you would add 15 to both sides, which would give you x=45<span />
<span>Since one standard deviation is 20 luggages, 3 standard deviations above the mean is 3*20=60 luggages above the mean of 380 luggages, so 60+380 gives the answer C, 440.</span>
You do 304 subtract 217 which equals 87
Im pretty sure the correct answer is the fourth one
