Upper bounds and lower bouds

Hi,
I am just quite confused with upper bounds and lower bouds.
Say the lenght of a rectangle is 7cm
Will the upper bound be 7.45 cms and the lower bound be 6.55 cms
Is that right ?

And moreover say if the lenght of a rectangle is 7.5 cms
what will be the upper bound and lower bounds

Anyhelp would be greatly appreciated
-Thanks

Reply 1

adz1991

What has the orignal amount been rounded to, as in 1cm, ect

Reply 2

DAVE 101

4

Part one of this thread...upper bound, technically, is 7.4999r. but we've been told to just say 7.5. The lower bound is 6.5.

Part two, similarly the upper bound of 7.5 is 7.54999r, but call it 7.55. The lower bound of 7.5 is 7.45.

Correct me if I'm wrong, but I think that's right.

Reply 3

girl_in_black

16

barath90

Hi,
I am just quite confused with upper bounds and lower bouds.
Say the lenght of a rectangle is 7cm
Will the upper bound be 7.45 cms and the lower bound be 6.55 cms
Is that right ?

And moreover say if the lenght of a rectangle is 7.5 cms
what will be the upper bound and lower bounds

Anyhelp would be greatly appreciated
-Thanks

If it's 7cm correct to the nearest full number, it would be 6.5 and 7.5.

For the second one, if its correct to 2 s.f. (it will tell you this in the question) it would be 7.45 and 7.55.

Reply 4

barath90

OP

girl_in_black

If it's 7cm correct to the nearest full number, it would be 6.5 and 7.5.

For the second one, if its correct to 2 s.f. (it will tell you this in the question) it would be 7.45 and 7.55.

it says 7cm to the nearest integer

???

barath90

it says 7cm to the nearest integer

an integer is a whole number (can be positive, negative and just 0) so what i said is correct :smile:

Reply 7

lol2003

6.5 and 7.5 arn't integers though? i'm confused, sorry.

Reply 8

girl_in_black

16

lol2003

6.5 and 7.5 arn't integers though? i'm confused, sorry.

no, but the question is saying that 7 was rounded to the nearest whole number, therefore it could have been anything between 6.5 and 7.5 before it was rounded.

Reply 9

barath90

OP

The next sum :

formula g = 2L/T^2 sinx

To calculate an estimate for g

T = 1.3 correct to 1 decimal place
L = 4.50 correct to 2 decimal places
x = 30 correct the nearest integer

Calculate the upper bound and lower bound of g nearest to 3 centimentes.

The only doubt i have in this sum is will the upperbound of 1.3 be 1.35 and the lower bound be 1.25

Reply 10

girl_in_black

16

barath90

The next sum :

formula g = 2L/T^2 sinx

To calculate an estimate for g

T = 1.3 correct to 1 decimal place
L = 4.50 correct to 2 decimal places
x = 30 correct the nearest integer

Calculate the upper bound and lower bound of g nearest to 3 centimentes.

The only doubt i have in this sum is will the upperbound of 1.3 be 1.35 and the lower bound be 1.25