# Frequency Distribution-Normal Distribution-Eye Inspection

• Jan 22nd 2009, 11:35 AM
KayPee
Frequency Distribution-Normal Distribution-Eye Inspection
How can we tell when a frequency distribution is normally distributed.

The frequency distribution below on eye inspection appears to have a normal distribution b'cos :

The frequency starts low and then increase to some maximum then decrease to a low frequency.

Is my observation right?

Thanks

Selling prices of Pontiac/Frequency
(\$ 000)

60-64/1
65-69/4
70-74/5
75-79/15
80-84/7
85-89/6
90-94/1
• Jan 22nd 2009, 01:11 PM
mr fantastic
Quote:

Originally Posted by KayPee
How can we tell when a frequency distribution is normally distributed.

The frequency distribution below on eye inspection appears to have a normal distribution b'cos :

The frequency starts low and then increase to some maximum then decrease to a low frequency.

Is my observation right?

Thanks

Selling prices of Pontiac/Frequency
(\$ 000)

60-64/1
65-69/4
70-74/5
75-79/15
80-84/7
85-89/6
90-94/1

I suggest you apply a goodness-of-fit test.
• Jan 22nd 2009, 02:23 PM
KayPee
goodness-of-fit test
Quote:

Originally Posted by mr fantastic
I suggest you apply a goodness-of-fit test.

Mr Fantastic

This is the first time I ever heard of this test.

How would I apply that to the data above.

Besides would you consider 'eye inspection' a 'no-no'.
• Jan 22nd 2009, 05:55 PM
mr fantastic
Quote:

Originally Posted by KayPee
Mr Fantastic

This is the first time I ever heard of this test.

How would I apply that to the data above.

Besides would you consider 'eye inspection' a 'no-no'.

An 'eye inspection' gives you an idea of the sort of distribution you might want to test against.

goodness of fit distribution - Google Search=