Plotting Scatter Graphs - Mr-Mathematics.com - Free Printable

Let’s solve this step by step.

We are given data for 10 students: how many minutes they spend reading per day and how many minutes they spend watching TV per day. We need to plot these as points on a scatter graph, with “Time spent watching TV per day (mins)” on the x-axis and “Time spent reading per day (mins)” on the y-axis.

Then we’ll look at the pattern of the points to see if there’s any correlation — meaning, do the two things tend to go together in some way? For example, does more TV time mean less reading time? Or more reading time mean more TV time? Or no clear pattern?

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Step 1: List all the data pairs (TV time, Reading time)

From the table:

- (60, 30)
- (55, 30)
- (60, 35)
- (40, 40)
- (35, 40)
- (30, 45)
- (35, 45)
- (25, 50)
- (20, 55)
- (20, 55) ← Wait, last row says 55 mins reading and 20 mins TV → so (20, 55)

Actually, let me double-check the table from top to bottom:

Row 1: TV=60, Read=30 → (60,30)
Row 2: TV=55, Read=30 → (55,30)
Row 3: TV=60, Read=35 → (60,35)
Row 4: TV=40, Read=40 → (40,40)
Row 5: TV=35, Read=40 → (35,40)
Row 6: TV=30, Read=45 → (30,45)
Row 7: TV=35, Read=45 → (35,45)
Row 8: TV=25, Read=50 → (25,50)
Row 9: TV=20, Read=55 → (20,55)
Row 10: TV=20, Read=55 → (20,55) ← same as above? Actually, looking again — yes, both row 9 and 10 have TV=20, Read=55. So two points at (20,55).

Wait — actually, let me check the original table again carefully:

Looking back:

The table has:

Time spent reading | Time spent watching TV
30 | 60
30 | 55
35 | 60
40 | 40
40 | 35
45 | 30
45 | 35
50 | 25
55 | 20
55 | 20

So actually, the LAST TWO rows are BOTH (TV=20, Read=55). So yes, two identical points.

But in scatter graphs, even if two points are the same, you still plot them — sometimes you might draw a small circle or just put one dot but know it represents two people.

Now, let’s list all 10 points clearly:

1. (60, 30)
2. (55, 30)
3. (60, 35)
4. (40, 40)
5. (35, 40)
6. (30, 45)
7. (35, 45)
8. (25, 50)
9. (20, 55)
10. (20, 55) ← duplicate

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Step 2: Plot each point on the graph

X-axis: Time spent watching TV (from 10 to 65)
Y-axis: Time spent reading (from 20 to 55)

Let’s imagine plotting them:

- At TV=60, we have two points: Read=30 and Read=35 → so (60,30) and (60,35)
- At TV=55, Read=30 → (55,30)
- At TV=40, Read=40 → (40,40)
- At TV=35, we have two points: Read=40 and Read=45 → (35,40), (35,45)
- At TV=30, Read=45 → (30,45)
- At TV=25, Read=50 → (25,50)
- At TV=20, we have two points: both Read=55 → (20,55) twice

If we sketch this mentally or on paper, what do we see?

As TV time goes DOWN (from 60 to 20), reading time goes UP (from 30 to 55). That suggests an inverse relationship — when one increases, the other decreases.

This is called a negative correlation.

Let’s verify with a few examples:

- Student with most TV (60 mins) reads only 30 or 35 mins.
- Student with least TV (20 mins) reads 55 mins.
- Middle values: TV=40 → Read=40; TV=35 → Read=40 or 45; TV=30 → Read=45.

Yes — generally, as TV time decreases, reading time increases.

Even though there are a couple of points that don’t perfectly follow (like TV=35 has both 40 and 45 reading), the overall trend is clear.

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Step 3: Conclusion

When we plot all the points, they form a downward-sloping pattern from left to right. This means there is a negative correlation between time spent watching TV and time spent reading.

In simple terms: The more time students spend watching TV, the less time they tend to spend reading — and vice versa.

Final Answer: There is a negative correlation between time spent watching TV and time spent reading.