You are Here: Home >< Maths

# S3 Confidence intervals

Announcements Posted on
Four hours left to win £100 of Amazon vouchers!! Don't miss out! Take our short survey to enter 24-10-2016
1. This seems a stupid question but why does it equal to 6.86 and not 5?
I know 5 would just give me 1.96 again but I dont understand the 6.86
2. (Original post by RK1998)
This seems a stupid question but why does it equal to 6.86 and not 5?
I know 5 would just give me 1.96 again but I dont understand the 6.86

.
3. (Original post by Zacken)
.
So it's just the difference of the intervals divided by 2.
Thank you so much

Posted from TSR Mobile
4. (Original post by RK1998)
So it's just the difference of the intervals divided by 2.
Thank you so much
Yes, you know the width of an interval is given by but the width here is the difference of the limits.

So and then dividing both sides by 2 gets you your answer.

You're very welcome.

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: April 15, 2016
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:
Today on TSR

### Who is getting a uni offer this half term?

Find out which unis are hot off the mark here

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams