The mean weight of the packages Joan shipped was 2.5 pounds. If Joan mailed four packages and three of them had weights of 1.8, 3.2 and 2.7 pounds, then what did the other package weigh?

2.8
2.3
3.3

2.3 is the answer

Step-by-step explanation:

Name the unknown package n

[1.8 + 3.2 + 2.7 + n]/4 = 2.5

[7.7 + n] = 2.5 × 4

7.7 + n = 10

n = 10 - 7.7

n = 2.3

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

i think it is 18

step-by-step explanation: