Given old number, total values, 2 new inputs, find new mean

[JAsh]

Find the average......................?
The 45 students in a class each recorded the number of whole minutes, x, spent doing experiments on Monday. The results are
total x= 2230

Find the mean number of minutes the students spent doing experiments on Monday.

^that one i can do, but its the next one i dont know

two new students joined the class and reported that they spent 37 minutes and 30 minutes respectively.
calculate the new mean including these two students.

 

[sgtpepper]

Re: Find the mean...

2230 represents the total number of minutes 45 students spent, if you divide 2230 by 45, you will figure out the average time spent by each student. You say you already know how to do this though. So, how is the second question different? In this case, you add two students (45+2) and 67 minutes (2230+30+37).

Now your total number of minutes is just:

2230 + 30 + 37 = 2297 minutes

and your number of students is:

45 + 2 = 47

So your average number of minutes every student spent on the lab is just the new total number of minutes divided by the new number of students:

2297 / 47 = ?


I hope I interpreted that correctly and if I did, I hope that helps you.

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