Hi ActEd. I have a question about one of the CT6 online classroom videos. In the video clip "Question: 106, April 2002 Q10(i)", at the 7min mark, the tutor says the value on the left can be simplified to the value on the right (see attachment). I understand the summation is from 1 to 10, so the 10 probably comes from this, but I don't understand how the two equations below can equate if (a-b)^2=a^2 + b^2 -2ab. Can you clarify this for me?
You would get a quicker response asking in the CT6 online classroom forum as you have dedicated tutors there to answer queries. I think \(\mu\) should say \(\hat \mu\) then it would work.
