Math Is Fun Forum

morik

Member

Registered: 2005-11-23

Posts: 16

Hows about a little help here

Hey guys,
Got a few questions here. I know they are probably no more than GCSE standard but still, I need and appreciate the help.

The scenario is I work for a computer repair company.

1. During January, the following faults were recorded

Number    Fault
100           Hard Disk Drive
300           Power Supply
150           Operating System
200           Video Card
180           Wiring
30               Nil

Express each fault occurrence as a percentage of the total number of faults.

2. During the year the following numbers of computers were received for repair

Jan - 960
Feb - 900
Mar - 800
Apr - 750
May - 600
Jun - 650
Jul - 600
Aug - 400
Sep - 600
Oct - 800
Nov - 200
Dec - 150

1.    What is the total number of computers received for repair?
2.    What is the mean number received per month?
3.    What is the median of the data above?
4.    What is the mode of the data above?

Thanks for your time.
Morik

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: Hows about a little help here

Is the Nil Fault an actual fault or a service call that was fixed some other way?
Do we count the Nil ones?

In second question, what does "mode" mean?

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igloo myrtilles fourmis

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Hows about a little help here

The mode is the most common number. Here, it is 600 because it appears three times. I'm quite surprised you didn't know that, John.

For the rest of 2:

1. Just add up all of the numbers for each month.
2. Take your answer to 1) and divide it by 12 (the number of months)
3. Arrange the numbers in order and pick the middle one. Here, that is halfway between the 6th and 7th ones, so just take the mean of those.
4. As above, it is 600 because it is the most common.

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Why did the vector cross the road?
It wanted to be normal.

morik

Member

Registered: 2005-11-23

Posts: 16

Re: Hows about a little help here

Thanks for the help guys. As for the first question, "Nil" is an actual fault so must be counted.

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: Hows about a little help here

Nil  3.125%
because 30 / (100+300+150+200+180+30) = 0.03125
Move decimal over two to the right to make a percent.  .03125 is then 3.125% or 3 and 1/8 percent.

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igloo myrtilles fourmis