I know I am asking a lot of questions

-1.2 Degree Fahrenheit.

Step-by-step explanation:

Since,

The average daily changes,   total changes/number of days

Here,

The total changes = - 16.8° F ( - sign shows the decreasing )

And, the number of days = 14

So,

The average daily rate of change in the high temperature in degrees Fahrenheit is -1.2° F.

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