x Turn on thread page Beta
 You are Here: Home >< Maths

# upper bounds and lower bounds need help asap :) watch

1. there are quite a few questions and it would mean the world to me if you could help!
1. The crowd at a stadium was quoted as being 80000. It is known that this number was rounded to two significant figures. Calculate the lower bound and upper bound.

2. find the upper and lower bounds of the following numbers (accuracy of measurement given in brackets):
a.26 miles (1s.f.)
b.0.0034kg (2 s.f.)
c.0.20 litres (2 d.p.)
d.800 metres (nearest 10 metres)
e.100m (nearest centimetre)
f. 4 litres (nearest half a litre)
2. For question one if the crowd has 80,000 people in it rounded to two significant figures, that means that then hundreds digit must have been rounded either down or up to get 80,000.

For example it could have been 80,112 people in reality, rounded down to 80,000. So for your upper bound find the largest number that can be rounded down to get 80,000.

And for your lower bound instead of 80,000, it will be under 80,000. So find the smallest number which you can round up to get 80,000. It will look something like 79,xxx

Follow the same thinking for the next question as well
3. (Original post by Mr. Ee)
For question one if the crowd has 80,000 people in it rounded to two significant figures, that means that then hundreds digit must have been rounded either down or up to get 80,000.

For example it could have been 80,112 people in reality, rounded down to 80,000. So for your upper bound find the largest number that can be rounded down to get 80,000.

And for your lower bound instead of 80,000, it will be under 80,000. So find the smallest number which you can round up to get 80,000. It will look something like 79,xxx

Follow the same thinking for the next question as well
thanks!!!
4. because "people in a crowd" is a type of discrete data you have to be careful with the upper bound.

80 000 to 2 s.f is the same as 80 000 to the nearest 10 000...

you add 5000 and minus 5000 to get 75 000 and 85 000; but then you must subtract one unit from the upper bound.

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: October 31, 2015
Today on TSR

### How much will your degree earn you?

Find out where yours ranks...

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams