# Graphical presentation of the relationship between two variables is

A graphical presentation of the relationship between two quantitative variables is a. A pie chart b. a histogram c. a bar chart d. a scatter diagram ANS: D Answer to A _____ is a graphical presentation of the relationship between two quantitative variables. 1) histrogram 2) bar chart 3. We may wish to display two variables and their associations for a group of individuals. idea of the relationship between the variables across individuals is obtained. Even if the plot is not used in the final presentation, it may highlight outliers.

Dot plots can be used to look at whether values in one group are typically different from values in another group. In the example above, the plot shows it typically takes slightly longer for a scorpion to catch a prey with low activity than high activity.

Archives of Disease in Childhood,;71,F Horizontal bars denote medians for each group.

**Linear Equations in 2 Variables – Graphs 01**

The table below shows how social class varied between the two areas of the baby check scoring system. In both areas the mothers were mostly from social class III manual. This table shows how illness severity was related to baby-check score.

We can see the association of increasing severity with increasing score. The initial impression was not recorded for two babies. Neonatal morbidity and care-seeking behaviour in rural Bangladesh. Journal of Tropical Pediatrics,47, Amongst other things, the first table below shows how medically unqualified practitioners were used most often for all recorded forms of morbidity and for more than one in three skin rashes no care was sought.

In the second table we see that care from the district hospital appears to be the most expensive option, followed by private practitioners and village doctors. Three dimensional bar-charts can be used to show the numbers in each section of the table.

However, whilst these may look quite impressive, they do not generally make interpretation any simpler and may even 'lose the numbers'. Cardia et al, Outcome of craniocerebral trauma in infants and children, Childs Nerv.

The information shown above gender and age group could be given in a 2x3 table two rows: The three dimensional bar-chart replaces each of the six numbers with a bar of the appropriate height; however, because of the three dimensional aspect of the display it is not possible to read off the original numbers.

The display is used to impart only 6 figures, and it has lost those! It appears that for most of the years ozone was the major component of air quality standard. In sulphur dioxide was the main feature.

It is not possible to read off the actual figures. This data could have been shown as a 7x5 table.

These displays may look impressive, but they are not generally an effective way of imparting the information with minimal loss of relevant information.

Side-by-side or stacked bar charts may be an effective way of presenting data on two categorical variables. The following three examples of side by side bar charts show the data more effectively than the corresponding 5x4, 3x3 and 2x7 contingency tables would.

Farmer P et al. Community based treatment of advanced HIV disease: Bulletin of the World Health Organisation,79 12 Journal of Tropical Pediatrics,47, The following stacked bar chart is a very effective means of illustrating the fall in neural tube pregnancies over the years together with the increasing terminations, probably reflecting earlier detections in later years.

- The graphical relationship between a function & its derivative (part 1)

Hey et al, Use of local neural tube defect registers to interpret national trends, Archives of Disease in Childhood,;71,F Occasionally a picture may help the presentation.

Wound location by pathology group. Same data for the group with Charcot related ulceration. The slope seems to be positive, although it's not as positive as it was there.

### The graphical relationship between a function & its derivative (part 1) (video) | Khan Academy

So the slope looks like it is-- I'm just trying to eyeball it-- so the slope is a constant positive this entire time. We have a line with a constant positive slope.

So it might look something like this. And let me make it clear what interval I am talking about. I want these things to match up. So let me do my best. So this matches up to that. This matches up over here. And we just said we have a constant positive slope. So let's say it looks something like that over this interval. And then we look at this point right over here. So right at this point, our slope is going to be undefined. There's no way that you could find the slope over-- or this point of discontinuity.

## Graphical Displays: Two Variables

But then when we go over here, even though the value of our function has gone down, we still have a constant positive slope.

In fact, the slope of this line looks identical to the slope of this line. Let me do that in a different color. The slope of this line looks identical. So we're going to continue at that same slope. It was undefined at that point, but we're going to continue at that same slope.

And once again, it's undefined here at this point of discontinuity. So the slope will look something like that. And then we go up here. The value of the function goes up, but now the function is flat. So the slope over that interval is 0.

The slope over this interval, right over here, is 0. So we could say-- let me make it clear what interval I'm talking about-- the slope over this interval is 0. And then finally, in this last section-- let me do this in orange-- the slope becomes negative.

But it's a constant negative. And it seems actually a little bit more negative than these were positive. So I would draw it right over there. So it's a weird looking function. But the whole point of this video is to give you an intuition for thinking about what the slope of this function might look like at any point.