During one term in Math 310, Min Lee took seven tests, the last of which carried twice the weight of each of the others when averages were computed. Min’s test-score vector for the term was [84,78,91,80,72,88,83]. Show that Min’s final average, a weighted average, can be calculated as a dot product of this vector with another seven-component vector. How can the teacher obtain a class list of test averages by multiplying two matrices?

Answer 1

multiply it by the vertical matrix
1
1
1
1
1
1
2
then you get a sum, divide by 8 and you have the weighted average.

Answer 2

ok thx

Answer 3

wait actually is it divide by 7 or 8? shouldn't it be 7?