Find the mean of the first four test scores first.
(Add all numbers in set and divide by how many numbers there are)
81 + 87 + 71 + 89 = 328 / 4 = 82
Then, find the mean with the 85 added as the fifth term.
81 + 87 + 71 + 89 + 85 = 413 / 5 = 82.6
The impact that the 85 had on the mean test score was that the mean/average increased by 0.6.
Sorry for taking so long, it wont let me type a while ago. I have it all fix now hehe. I took a picture of my work, ask me if you still don’t understand.
Answer:
2 1/2 hours
Step-by-step explanation:quarters means 1/4 and there are 4 of them in each hours so if you have 10 quarters of a hour they add up to 2 hours and a half, because 2 hours times 4 equals 8 quarters and then add the other 2 quarters and you get half