Question

Which change could not affect the mode?
21, 19, 38, 24, 20, 3, 21, 23

eliminating the outliers

adding the data point 23 to the set

decreasing each number by 1

increasing each number by 2

Answer 1

i'd go with the first one

Answer 2

the mode is the number that occurs the most

i see 21 twice

eliminate the outliers which are the biggest and smallest number 3,38
the mode is still 21

if you add 23 then there are
two modes 23 and 21

if you decrease every number by 1 then mode has changed from 21 to 20

and if you increase every number by 2 then the mode has increased from 21 to 23