Math of data management

[kingwinner]

1) When there is a set of data, I don't know how to classify into intervals!

 

There is a formula:

interval width = data range / number of intervals

 

But I don't know how to use it! For example, the following are the golf scores of a tournament

10 12 23 35 34 36 47 58 60

Data range=60-10=50

Say, I want 5 intervals!

 

interval width=50/5=10

So interval width is 10

10-20

20-30

30-40

40-50

50-60

This is not working becuase a golf score of, say, 20 would fall in two intervals, what should I do?

 

 

2)

2a) In what year did the price first rise above $1.50?

2b) List the domain and range of these data.

 

[For 2a), would the answer be year 1997 or 1998? Is the graph saying that the price rises above $1.50 when year=1997.5?]

[For 2b), the domain would be 1996<x<2001, but is it element of real numbers or integers? The data points are (1996,1.43) (1997, 1.45) (1998,1.52) and so on, but on the graph all the points are connected, is this considered to be having a continuous data points?

 

If someone knows this topic well, please help me! I am struggling through it! Thank you!

[C1ay]

1) So interval width is 10

10-20

20-30

30-40

40-50

50-60

This is not working becuase a golf score of, say, 20 would fall in two intervals, what should I do?

These intervals are not 10 units in size, they are 11 units in size.

 

On your second question, in what year did the first occurence actually occur? Bear in mind that even if it occured on Dec. 31 it would still not be the New Year yet. For part b I would see Domain and Range at MathWorld.

[kingwinner]

These intervals are not 10 units in size, they are 11 units in size.

 

On your second question, in what year did the first occurence actually occur? Bear in mind that even if it occured on Dec. 31 it would still not be the New Year yet. For part b I would see Domain and Range at MathWorld.

1) But 20-10=10, so the intervals are indeed 10 units in size...

 

2) The graph seems continuous, but the data points seems discrete...that's how I get confused and can't decide whether the answer is 1997 or 1998...

 

3) The graph seems continuous, but the data points seems discrete, then would the domain be the element of real numbers or integers?

[C1ay]

1) But 20-10=10, so the intervals are indeed 10 units in size...

Get out your fingers and count the numbers from 10 through 20 including the 10 and the 20, you'll find there's 11 of them.....

 

The point in question occurs before the beginning of 1998.

 

The domain is the X axis and the range is the Y axis.