STATistics help!

[alevelstudents73]

I am doing this question right now but I dont understand how I can find out the unknown data becazse I never did this at school And also I am confused by the frequency because i thoight that you would have to divide everything by 10 to get the mean because that is the amount if values

 

[tkhunny]

I am doing this question right now but I dont understand how I can find out the unknown data becazse I never did this at school And also I am confused by the frequency because i thoight that you would have to divide everything by 10 to get the mean because that is the amount if values
View attachment 10219

1) Too small. Can't read it.
2) If this is foreign to you, why have you been given this problem?
3) If this is a Placement Test, you should get it wrong so that you can be put in the right class and actually study the material.

 

[Harry_the_cat]

I can't read it, but the frequency tells you the number of times that value occurs. So if you had, for example:

x	f
1	3
2	5

That means you have three 1s and five 2s. So if you wrote them all out (which you wouldn't) you would have:

1, 1, 1, 2, 2, 2, 2, 2.

Obviously you have 8 numbers in total (that is the sum of the f's)

The sum of these numbers is 1+1+1+2+2+2+2+2 = 3x1 + 5x2 (that is the sum of fx)

Make sense?