# Help with Means

• Oct 25th 2007, 07:40 AM
sammyfox07
Help with Means
Hello, can anybody please explain this question to me and show me how to work it out please. :confused:

Q1. Florence recorded her test results in the back of her exercise book.

She says. 'My mean mark in these five tests was 78%'

Unfortunately, Florence noticed that there was an ink blot covering her mark in art. Can you help her to work out her mark for art?

Thanks for you help kalagota but i still don't know what mark florence got in art
• Oct 25th 2007, 07:53 AM
kalagota
Quote:

Originally Posted by sammyfox07
Hello, can anybody please explain this question to me and show me how to work it out please. :confused:

Q1. Florence recorded her test results in the back of her exercise book.

She says. 'My mean mark in these five tests was 78%'

Unfortunately, Florence noticed that there was an ink blot covering her mark in art. Can you help her to work out her mark for art?

you know that mean is equal to the sum of the five tests divided by 5..
it was said that 78% was the boy's mean.
therefore, sum of the five tests over 5 is 78%.
but since the fifth one was erased, let it be equal to x.
so, sum of the four exams plus x all over 5 is still 78%.
hence, sum of the four exams plus x = 5* 78% = 390%.
therefore, x= 390% - sum of the four exams.. Ü