2+10+16+27+18=73 tests taken. Half the scores (36) are above the middle, and half the score are below the middle(another 36) so we're looking for score #37(the one that IS the middle) . (36+1+36=73) Now go back and look at the distribution: 50-59 are below the middle score, so 36-2 leaves 34. 60-69 ...