3/4 + (-3/8) = ? i know the answer but i still dont get how that answer was gotten so please put work!

Lab 1: central tendency and standard deviation directions: use excel to compute descriptive statistics. problem: you are the manger of a fast food store. part of your job is to report to the boss at the end of each day which special is selling best. use your knowledge of descriptive statistics and write one paragraph to let the boss know what happened today. here are the data. use excel to compute important values (mean, median, mode, and standard deviation). make sure to include a copy of your work. this should be submitted via canvas (no exceptions). make sure you include your excel work in addition to a summary of the results. special number sold cost huge burger 20 $2.95 baby burger 18 $1.49 chicken littles 25 $3.50 porker burger 19 $2.95 yummy burger 17 $1.99 coney dog 20 $1.99 total specials sold 119