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Interpreting
Graph Trends

Learn to read graphs like a detective: spot increases, decreases, and flat sections to answer SSAT questions with confidence.

SSAT Middle Level: Quantitative

What Is a Graph Trend?

A trend is the general direction a graph is moving over time. When you look at a line on a graph, you're asking: is it going up, going down, or staying flat?

Increasing
The line moves upward from left to right. Values are getting larger.
Decreasing
The line moves downward from left to right. Values are getting smaller.
Constant
The line stays flat. Values remain about the same.

Seeing Trends Visually

Time Value Increasing Constant Decreasing

Why Trends Matter on the SSAT

The SSAT will show you a graph and ask you to select a statement that correctly describes what the data shows. You won't need to calculate anything: you just need to read the trend accurately.

Read
Identify what the axes represent and what each data point means.
Describe
Put the trend into words: "As time increases, sales decrease."
Match
Find the answer choice that matches your description exactly.

The Core Rule of Graph Reading

Left Right Line rises → Increasing trend

Steepness Tells You Speed

Time (months) Growth Steep = fast change Gentle = slow change

Trend vs. Exact Value

Students often confuse reading the trend (the overall direction) with reading an exact value (a single data point). SSAT trend questions ask about direction, not specific numbers.

Trend Question Exact Value Question
Asks about Overall direction of the line A specific number at a point
Example "Sales increased over time" "Sales were 200 in March"
You look at The shape and slope of the line Where a point meets the axis
Key words increase, decrease, steady how many, what value

The 4-Step Method

1
Read the axes. Check what the \( x \)-axis and \( y \)-axis represent. Units matter!
2
Scan left to right. Follow the line from the left side to the right side. Does it go up, down, or stay flat?
3
Describe in words. Say it to yourself: "As [x-axis label] increases, [y-axis label] [increases/decreases/stays the same]."
4
Match the answer. Find the choice that matches your description. Eliminate choices that contradict the graph.

Worked Example 1

Month Books Sold 0 50 100 150 200 Jan Feb Mar Apr May Jun 30 60 100 140 170 200

Worked Example 2: Multiple Trends

Hour of Day Temperature (°F) 40 50 60 70 80 6am 8am 10am 12pm 2pm 4pm Rising Flat Falling

Worked Example 3: Bar Graphs

Subject Students 0 10 20 30 40 Math Science English Art Music 15 30 20 35 25

Finding the Greatest Change

Week Points 0 20 40 60 80 1 2 3 4 5 +35 pts 10 15 50 55 75

Reading Between the Lines

Sometimes the SSAT asks you to predict what comes next, or to identify what probably happened between two data points. This is called interpolation (between points) or extrapolation (beyond the data).

Interpolation
Estimating a value between two known points. Follow the line's direction between them.
Extrapolation
Predicting a value beyond the data. Continue the trend forward or backward.

Tricky Graph Language

The SSAT uses specific words to describe trends. Knowing the difference between these phrases can help you avoid trap answers.

1
"Steadily increased" means the line goes up at a consistent rate: it doesn't speed up or slow down much.
2
"Rapidly increased" means the line goes up steeply: a large change in a short time.
3
"Remained constant" means the line is flat or nearly flat: no significant change.
4
"Fluctuated" means the line goes up and down repeatedly: no single clear trend.

Common Mistakes

✕ Ignoring the Axes
Jumping to the line without checking what the axes represent. The same shape could mean completely different things.
✕ Confusing Direction
Saying the graph "decreases" when it actually increases. Always read left to right, not right to left.
✕ Over-Extrapolating
Assuming a trend will continue forever. A graph that rises may level off or drop: only describe what you see.

Summary Cheat Sheet

What You See Trend Name What to Say
Line goes up Increasing "As \(x\) increases, \(y\) increases"
Line goes down Decreasing "As \(x\) increases, \(y\) decreases"
Line stays flat Constant "\(y\) remained the same"
Steep line Rapid change "Large change in a short time"
Gentle line Gradual change "Small change over a long time"
Line goes up and down Fluctuation "Values varied with no clear trend"

Question 1 of 5

Day Lemonade Cups Mon Tue Wed Thu Fri 10 20 30 25 40

Based on the graph above, which statement is most accurate?

Question 2 of 5

Year Population 2018 2019 2020 2021 500 480 460 440 500 440

The graph shows the population of a town from 2018 to 2021. Which statement best describes the trend?

Question 3 of 5

Month Temperature (°F) Jan Feb Mar Apr May 30 32 46 58 70

Between which two months did the temperature show the greatest increase?

Question 4 of 5

Hour Cars in Lot 8am 10am 12pm 2pm 4pm 20 60 60 60 30

Which statement correctly describes the parking lot data?

Question 5 of 5

Week Miles Run 1 2 3 4 5 3 5 4 7 6

A student tracked the number of miles they ran each week. Which statement best describes the trend?