Urgently need help with this Maths related problem

[Grand Fromage]

"Roll a dice, if the dice shows 6, Tick YES.
In the dice shows another number, answer the question truthfully."

Have you ever lost your mobile phone?

YES or NO"

450 people were surveyed, 130 people ticked the yes box.

Estimate the proportion of people who have lost their mobile phones.

Give your answer to 1 d.p in %

Please explain the steps taken as well!

Am 'helping' son with his maths homework.

[RJE1966]

It's 'Math' FFS.

[Baby Huey]

I'm sure most people have lost a mobile at some point.

[Size Nine Elm]

1/6 of the people ticked the yes box because they threw a six - thats 75.

Out of the remaining 375 people, 55 ticked the box because they'd lost their phone, so 14.7%

ETA: Thats an estimate since we don't know precisely the proportion of those who threw a six have lost their mobile phone, but would assume its not statistically too different from the 5/6 we know about.

ETA2: got the principles right but the arithmetic wrong - doh.

ETA3: its also an estimate since we don't know exactly how many people threw a six, the 1/6 is a reasonable estimate.

So within the bounds of the problem, stating it to .1% is too precise...

Edited by Size Nine Elm on Thursday 22 January 21:12

[jsc15]

Only 5/6 of people were given the chance to reply to the mobile question. The other 6th said "Yes" as a requirement. 1/6 of 450 is 75 so 55 out of the remaining 375 were actually really surveyed which is 55/375 which is 14.7%

[Gemsbok1000]

RJE1966 said:

It's 'Math' FFS.

Tongue-in-cheek, I trust?

[tubbystu]

4.8%

450 divided by 130 x 100 = 28.8888888888888888888888888888888888888888888 multiply by 1/6 = 4.81481481481481481 , round up to 1 dp = 4.8 surely ?

Or have I missed the obvious

sorry just re-read the question - ignore my stupidity

Edited by tubbystu on Thursday 22 January 21:10

[Snake the Sniper]

Well, 75 people (1 in 6) tick yes regardless, so they have to be discounted. That leaves 55 out of 375 people who have lost their phone. So I'd go 14.7% (14.6666666%)

[2 sMoKiN bArReLs]

tubbystu said:

4.8%


Or have I missed the obvious

Yes

[Gemsbok1000]

Is it me or is everyone missing the point to the question?

[mft]

Grand Fromage said:

"Roll a dice, if the dice shows 6, Tick YES.
In the dice shows another number, answer the question truthfully."

Have you ever lost your mobile phone?

YES or NO"

450 people were surveyed, 130 people ticked the yes box.

Estimate the proportion of people who have lost their mobile phones.

Give your answer to 1 d.p in %

Please explain the steps taken as well!

Am 'helping' son with his maths homework.

A sixth of 450 is 75, so if the dice rolling was perfectly balanced, 75/450 people ticked yes prior to answering the question.

130 - 75 = 55, suggesting 55 people, having rolled a number that wasn't 6, ticked yes.

However, only 450 - 75 people (= 375) actually had the chance to answer the question, having rolled 1 to 5.

Thus 55/375 people lost their phones, which is 14.66666666% (recurring).

[Grand Fromage]

2 sMoKiN bArReLs said:

On average 1/6 of 450 will roll a six = 75

130 answered yes, so 55 lost their phone

55/450 = 12.2% ?

But how many of those who rolled a six had also lost their phones?

I think we need the proportion of people who answered yes, find that of the people who rolled a six, no?

[TomE]

Grand Fromage said:

"Roll a dice, if the dice shows 6, Tick YES.
In the dice shows another number, answer the question truthfully."

Have you ever lost your mobile phone?

YES or NO"

450 people were surveyed, 130 people ticked the yes box.

Estimate the proportion of people who have lost their mobile phones.

Give your answer to 1 d.p in %

Please explain the steps taken as well!

Am 'helping' son with his maths homework.

Does ticking yes mean ticking yes on both the dice question and the mobile question?

If so, then as chance of throwing a six is 1/6, 130 divided by six is 21.6. Therefore the number of people who ticked yes for loosing their phone is 130-21.6 = 108.4.

130/450 = 24.08%

Could be wrong though.

ETA- Looks like I am!

Edited by TomE on Thursday 22 January 21:12

[voyds9]

450 people surveyed 1 in 6 of had to answer yes (75)

Actual number who lost phones = 55 (130-75) out of 375 (450-75)

55/375 x 100% = 14.6%

[TheEnd]

Size Nine Elm said:

1/6 of the people ticked the yes box because they threw a six - thats 75.

Out of the remaining 375 people, 65 ticked the box because they'd lost their phone, so 17.3%

you then have to add the 6 rollers who have lost their phone, but didn't get the chance to answer it

[2 sMoKiN bArReLs]

Snake the Sniper said:

Well, 75 people (1 in 6) tick yes regardless, so they have to be discounted. That leaves 55 out of 375 people who have lost their phone. So I'd go 14.7% (14.6666666%)

Good one! I was forgetting 1/6 didn't get to answer the question!

[RJE1966]

Gemsbok1000 said:

RJE1966 said:

It's 'Math' FFS.

Tongue-in-cheek, I trust?

God, yes......and with an inevitable sigh.

[2 sMoKiN bArReLs]

Grand Fromage said:

2 sMoKiN bArReLs said:

On average 1/6 of 450 will roll a six = 75

130 answered yes, so 55 lost their phone

55/450 = 12.2% ?

But how many of those who rolled a six had also lost their phones?

I think we need the proportion of people who answered yes, find that of the people who rolled a six, no?

Agreed.

[JayKaybi]

Snake the Sniper said:

Well, 75 people (1 in 6) tick yes regardless, so they have to be discounted. That leaves 55 out of 375 people who have lost their phone. So I'd go 14.7% (14.6666666%)

Of those 75, some will have lost their phone too.



ETA - damn, beaten to it.

Edited by JayKaybi on Thursday 22 January 21:15

[mft]

JayKaybi said:

Snake the Sniper said:

Well, 75 people (1 in 6) tick yes regardless, so they have to be discounted. That leaves 55 out of 375 people who have lost their phone. So I'd go 14.7% (14.6666666%)

Of those 75, some will have lost their phone too.

You can't be sure of that. You can only be sure of the people who definitely have lost their phone.