07 - Estimating - Estimer - Prévoir - 07
1 Are most of us average?
Why is the shape of this curve so well known?
Why is it fundamental to statistics?
If we classify the inhabitants of a town, the leaves on a tree..., according to a characteristic (size, weight, IQ, level of competence...) the more one approaches the average for each criterion the more individuals there are.
The further from the average, the fewer they are. At the extremities, there is almost no one.
The graphic representation of this fact is called a Gaussian curve. The universal character of the curve was originated by Laplace who said that Gaussian distribution is the accumulation of many small and independant factors.
2 How to borrow money?
- Pierre Simon de Laplace (1749-1827)
- Karl Friedrich Gauss (1777-1855)
You borrow 10000 €uros from your bank.
Is it more advantageous to repay at a fixed rate or at a variable rate?
Without algebra, how could one find out? Mathematics help us to understand and interpret these financial contracts.
To ignore them would be to be defenceless against commercial practice.
The situation is identical, but more complicated, with investments.
You deposit 10000 €uros in the bank: in exchange the bank undertakes to return this amount with interest -eventually- dependent on the monetary and stock exchange index. Who is the winner ?
Take a plane to Germany*
1• Take a phone book of the country
2• Board the plane
3• When you cross the border, open the phone book
4• Choose a name at random, note its telephone number and slip it into your pocket
5• Put on a parachute
6• Open the door of the plane and...
7• On landing, walk at random, straight ahead
8• Ask the first person you meet for his name and telephone number
9• Compare with the name and number you put in your pocket
10• What luck! They are the same! You have won to Eurobingo!
- Germany has about 82 million inhabitants.
- So, their is a chance in 76 275 360
of winning the Jackpot!