Math Is Fun Forum

FRATQU33N

Member

Registered: 2016-08-21

Posts: 14

Probability Distrubutions

Hi Guys,

I have a lot of trouble interpreting worded questions regarding probability disn's.

In this particular case, could you explain how they answer can be intuitively derived?

Thank you so much for your time!

Q:

The times to failure of a certain brand of ink jet printer are approximately normally distributed with a mean of 1500 hours and a standard deviation of 200 hours.

(b) What should the guarantee time for these printers be if the manufacturer wants only 5% to fail within the guarantee period?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Probability Distrubutions

Hi;

Hint:

If you want intuitive then think like this, supposing I put the guarantee at 1100. That means only 2.5% of the time will the printer go down while it is under guarantee. So you are close, can you do the rest?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

FRATQU33N

Member

Registered: 2016-08-21

Posts: 14

Re: Probability Distrubutions

Yes, Thank you so much for your time!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Probability Distrubutions

Hi;

You are welcome, let me know if you need more.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.