The box plots show students' scores on a pre-test and a post-test.
which is the best estimate of the difference between the medians of the post-test and pre-test scores?
a. 5
b. 7
c. 12
d. 78.5

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b

the answer is 31.27mph