Jake's final grade in his science class is calculated by finding the mean of his scores for six project reports. the score jake received on his first five reports are 66,80,88,82, and 72.

what is the lowest-possible score jake can earn his last report in order to have at least an 80 for his final grade?

The lowest possible score that Jake can have is 92.

To solve a problem like this, you need to find the average of the data set.  To do that, you add up all the given numbers and divide the total by how many numbers were added up.  

To find this answer, I just added in each letter one at a time (for C, I did 66+80+88+82+72+92, which equals 480, and then I divided it by 6 to get 80.) until I got an answer of 80.