You are Here: Home >< A-levels

# Help with maths S1 revision? ? watch

1. Midpoint, m, of each interval are calculated and the data is coded by C=(m-170)/20.

c | frequency
160 <c <180 | 25
180 <c <200 | 32
200 <c <220 |26
220 <c <240 |31
240<c <260 | 16
260 <c <280 |7

Find mean and standard deviation of C.
Find mean and standard deviation of c.

2. (Original post by M12S)
Midpoint, m, of each interval are calculated and the data is coded by C=(m-170)/20.

c | frequency
160 <c <180 | 25
180 <c <200 | 32
200 <c <220 |26
220 <c <240 |31
240<c <260 | 16
260 <c <280 |7

Find mean and standard deviation of C.
Find mean and standard deviation of c.

Well... how do you calculate the mean given grouped frequencies?

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: February 2, 2017
Today on TSR

### Congratulations to Harry and Meghan!

But did you bother to watch?

Poll

## All the essentials

### Student life: what to expect

What it's really like going to uni

### Essay expert

Learn to write like a pro with our ultimate essay guide.

### Create a study plan

Get your head around what you need to do and when with the study planner tool.

### Resources by subject

Everything from mind maps to class notes.

### Study tips from A* students

Students who got top grades in their A-levels share their secrets