GCSE revision Maths

[Bruntburger]

My daughter is preparing for her maths exam tomorrow and has been working through this practice sheet.

Any ideas how to answer this question?

I would of just worked out the mean average but not allowed a calculator in the exam.

Any input from boffins welcome .....

 

[Bruntburger]

Before you ask I don't know how good each swimmer looks in a bikini?


Sent from my iPhone using Tapatalk

 

[chimneys]

Lizzie (just).

Not difficult to get means is it, even without a calculator.

Is there a catch?

 

[carteater]

I assume they want you to work out an average/mean without a calculator, EDIT the post below makes that very easy.
I always hated non-calculator maths papers.
It's Lizzie anyway.

 

[Aristotle]

Since they are all 26-something times, just add up the number after the decimal point in each case and divide by the number of times to get an average for each girl.

 

[Rod Marsh]

Since they are all 26-something times, just add up the number after the decimal point in each case and divide by the number of times to get an average for each girl.

correct.

 

[HAILSHAM SEAGULL]

Add Lizzie's 5 times up and divide by 5, this gives her average time.
Add Megans 6 times up and divide by 6 to give her average time.

 

[hans kraay fan club]

My daughter is preparing for her maths exam tomorrow and has been working through this practice sheet.

Any ideas how to answer this question?

I would of just worked out the mean average but not allowed a calculator in the exam.

Any input from boffins welcome .....

Because ALL the times are 26.X you can ignore the whole seconds and just work out the average of the .X part.

First swimmer is 20 tenths / 5 = 26.4
Second is 30 tenths / 6 = 26.5

Select the first.

 

[Bruntburger]

Because ALL the times are 26.X you can ignore the whole seconds and just work out the average of the .X part.

First swimmer is 20 tenths / 5 = 26.4
Second is 30 tenths / 6 = 26.5

Select the first.

That's great. Thank you all for your help.
Maths isn't my strong point!
Come to think of it neither is English.
Cheers

 

[dazzer6666]

Lizzie has a faster mean of 26.4 (vs 26.5) so I'd select her.
Whilst Megan has the overall single fastest time, this looks inconsistent with the rest of her performances (she is less consistent generally with a greater range of times)
Megan should be told not to use the vending machine after swimming, then she'll get faster and make the team next time

 

[Springal]

And regardless of the outcome of this exam, your daughter will be in a job where she can use a spreadsheet to work this stuff out rendering this Maths exam completely pointless.

 

[Goldstone1976]

Since it's a maths test, what you've been told is correct. In the real world, however, I might be inclined to pick the second swimmer, on the basis that her average time is only 0.1s slower than the first's but she has swum the fastest time. On her best day, she's the (slightly) faster swimmer.

 

[timbha]

Deduct 26secs from every trial, e.g. 1st one is 26.3 - 26 = 0.3

Add up the total of what's left and divide by number of swims for each swimmer,

Ave for Lizzie is 2.0/5 = 0.4 + 26 = 26.4
Ave for megan is 3.0/6 = 0.5 + 26 = 26.5

So Lizzie has faster average time, but
Megan had the fastest swim

Teacher has to decide if he/she wants the most consistent or fastest swimmer. Is this a trick question?

 

[Rod Marsh]

Alternatively you could discount the results where they have swum the same time. Then average what's left?

 

[Paul Reids Sock]

My wife had to resit her maths a few years ago. Big bit of advice I gave her that helped is always ignore the bloody story. It is there to throw you off half the time.

Once you stop thinking of swimming and such crap then it's a simple case of getting the mean.

Also, in this case you could argue that either is correct as the variation in times for the first girl is smaller so you have more of an idea where she will come. The second girl has shown she can swim a lot faster but also a lot slower. So the story here actually doesn't help at all or show what the teacher is after

 

[dazzer6666]

Since it's a maths test, what you've been told is correct. In the real world, however, I might be inclined to pick the second swimmer, on the basis that her average time is only 0.1s slower than the first's but she has swum the fastest time. On her best day, she's the (slightly) faster swimmer.

Freak performance based on normal average times - need to await results of drug tests

 

[whitelion]

And regardless of the outcome of this exam, your daughter will be in a job where she can use a spreadsheet to work this stuff out rendering this Maths exam completely pointless.

It still helps to be able to make calculations without the need of a spreadsheet or calculator - the methodology is the important thing.

What happens in a powercut/no computer/no calculator etc.?

 

[Springal]

It still helps to be able to make calculations without the need of a spreadsheet or calculator - the methodology is the important thing.

What happens in a powercut/no computer/no calculator etc.?

You go down the pub.

 

[timbha]

What's the most appropriate measure ?
Mean, median, standard deviation, average, fastest, slowest - each one could be relevant

 

[whitelion]

You go down the pub.

Nuff said.

That'll be the end of exercise.