# Thread: Starting value for a frequency diagram

1. ## Starting value for a frequency diagram

I have a list of average rainfall in inches, and I know the lowest value is 0.32 inches.

I am told the following: A frequency diagram of the data is required that uses groups of width
0.5 inches such that, for instance, all the recorded values from
0.5 inches up to but not including 1 inch are included in the same
group. The lowest rainfall is to be included in the first group.

Assuming that the rainfall was measured to the nearest one hundredth
of an inch, state the starting value of the first interval that you need
to use to obtain a frequency diagram with groups as described above.

My guess is 0.315, as when this is rounded to the nearest one hundredth it rounds up to 0.32, but I'm really not sure. And when I then construct a histogram with this starting value there's a gap between the y-axis and the first bar, which again I'm not sure is allowed. Can anyone help?

2. ## Re: Starting value for a frequency diagram

Originally Posted by alexlbrown59
I have a list of average rainfall in inches, and I know the lowest value is 0.32 inches.

I am told the following: A frequency diagram of the data is required that uses groups of width
0.5 inches such that, for instance, all the recorded values from
0.5 inches up to but not including 1 inch are included in the same
group. The lowest rainfall is to be included in the first group.

Assuming that the rainfall was measured to the nearest one hundredth
of an inch, state the starting value of the first interval that you need
to use to obtain a frequency diagram with groups as described above.

My guess is 0.315, as when this is rounded to the nearest one hundredth it rounds up to 0.32, but I'm really not sure. And when I then construct a histogram with this starting value there's a gap between the y-axis and the first bar, which again I'm not sure is allowed. Can anyone help?
don't bins of

[0,0.5), [0.5, 1), ... [k*0.5, (k+1)*0.5) for k=0, 1, 2

your first measurement, 0.32 falls into the first bin.
each bin has width 0.5
in bin 1, for example, all measurements from 0.5 to 1 but not including 1 are included.

Am I missing something?

3. ## Re: Starting value for a frequency diagram

Sorry but I don't really understand your answer...I think you're talking about decision maths and I haven't covered that. Could you explain it in simpler terms please?

4. ## Re: Starting value for a frequency diagram

Originally Posted by alexlbrown59