Nice work!
Review your answers above to learn from any mistakes.
About This Drill
ACT Science: Data Representation (Drill 1) is a Science practice drill covering Data Representation. It contains 5 original questions created by Brian Stewart, a Barron's test prep author with over 20 years of tutoring experience.
ACT Data Representation questions test your ability to read and interpret graphs, tables, and figures accurately. This drill uses figures showing soil water retention and drainage rates across four soil types, asking you to read data precisely, compare trends, and evaluate a student's claim.
Questions & Explanations
Figures 1 and 2
Soil scientists investigated how soil texture affects water retention and drainage. Four soil types; Sand, Sandy Loam, Silt Loam, and Clay, were each packed into identical 30 cm columns with sealed bottoms fitted with drainage valves. Each column was saturated with 500 mL of distilled water, and the valve was opened simultaneously for all columns. The volume of water drained (in mL) was recorded at 10-minute intervals for 60 minutes (Figure 1). After 60 minutes, the researchers measured the field capacity of each soil type, the percentage of total pore space remaining filled with water after free drainage had ceased (Figure 2).
Figure 1. Cumulative Water Drained vs. Time
Water Drained (mL)
Time (min)
0
100
200
300
400
500
10
20
30
40
50
60
Sand
Sandy Loam
Silt Loam
Clay
Figure 2. Field Capacity by Soil Type
(% pore space filled after free drainage ceased)
Field Capacity (%)
0
20
40
60
80
100
Sand
Sandy Loam
Silt Loam
Clay
Question 1. According to Figure 1, which soil type drained the most water in the first 10 minutes?
-
A) Clay
-
B) Silt Loam
-
C) Sandy Loam
-
D) Sand ✓
Explanation: At the 10-minute mark in Figure 1, the Sand line (blue) has risen to approximately 420 mL drained, far more than Sandy Loam (~250 mL), Silt Loam (~110 mL), or Clay (~20 mL). Sand has large pore spaces between particles that allow water to flow through very rapidly, producing the greatest drainage volume in the first 10 minutes.
Figures 1 and 2
Soil scientists investigated how soil texture affects water retention and drainage. Four soil types; Sand, Sandy Loam, Silt Loam, and Clay, were each packed into identical 30 cm columns with sealed bottoms fitted with drainage valves. Each column was saturated with 500 mL of distilled water, and the valve was opened simultaneously for all columns. The volume of water drained (in mL) was recorded at 10-minute intervals for 60 minutes (Figure 1). After 60 minutes, the researchers measured the field capacity of each soil type, the percentage of total pore space remaining filled with water after free drainage had ceased (Figure 2).
Figure 1. Cumulative Water Drained vs. Time
Water Drained (mL)
Time (min)
0
100
200
300
400
500
10
20
30
40
50
60
Sand
Sandy Loam
Silt Loam
Clay
Figure 2. Field Capacity by Soil Type
(% pore space filled after free drainage ceased)
Field Capacity (%)
0
20
40
60
80
100
Sand
Sandy Loam
Silt Loam
Clay
Question 2. Based on Figures 1 and 2, which soil type would be most suitable for agriculture that requires consistent moisture availability over time?
-
A) Sand, because it drains quickly and prevents waterlogging
-
B) Sandy Loam, because it has moderate drainage and moderate water retention based on the data shown
-
C) Silt Loam, because it has a high field capacity while draining at a moderate rate ✓
-
D) Clay, because it has the highest field capacity of the four soil types
Explanation: Consistent moisture availability requires both adequate water retention and sufficient drainage so roots are not waterlogged. Figure 2 shows Silt Loam has a field capacity of approximately 50%, higher than Sand (~15%) and Sandy Loam (~28%), but comparable to Clay (~55%). The key distinction is Figure 1: Clay drains almost nothing over 60 minutes, creating waterlogging conditions that deprive roots of oxygen. Silt Loam drains at a moderate rate while retaining substantial moisture, making it the best balance for agricultural use, a conclusion well supported by soil science literature.
Figure 1
Soil scientists investigated how soil texture affects water retention and drainage. Four soil types; Sand, Sandy Loam, Silt Loam, and Clay, were each packed into identical 30 cm columns with sealed bottoms fitted with drainage valves. Each column was saturated with 500 mL of distilled water, and the valve was opened simultaneously for all columns. The volume of water drained (in mL) was recorded at 10-minute intervals for 60 minutes (Figure 1). After 60 minutes, the researchers measured the field capacity of each soil type, the percentage of total pore space remaining filled with water after free drainage had ceased (Figure 2).
Figure 1. Cumulative Water Drained vs. Time
Water Drained (mL)
Time (min)
0
100
200
300
400
500
10
20
30
40
50
60
Sand
Sandy Loam
Silt Loam
Clay
Question 3. According to Figure 1, approximately how much water had drained from the Sandy Loam column after 20 minutes?
-
A) 100 mL
-
B) 175 mL ✓
-
C) 250 mL
-
D) 325 mL
Explanation: At the 20-minute mark, the Sandy Loam line (green) sits between the 100 mL and 200 mL gridlines, closer to the 200 mL line, approximately 175 mL. Reading graphs carefully means identifying which gridlines bracket the data point and estimating its position between them. Sandy Loam has drained more than Silt Loam or Clay by this point, but considerably less than Sand.
Figure 2
Soil scientists investigated how soil texture affects water retention and drainage. Four soil types; Sand, Sandy Loam, Silt Loam, and Clay, were each packed into identical 30 cm columns with sealed bottoms fitted with drainage valves. Each column was saturated with 500 mL of distilled water, and the valve was opened simultaneously for all columns. The volume of water drained (in mL) was recorded at 10-minute intervals for 60 minutes (Figure 1). After 60 minutes, the researchers measured the field capacity of each soil type, the percentage of total pore space remaining filled with water after free drainage had ceased (Figure 2).
Figure 2. Field Capacity by Soil Type
(% pore space filled after free drainage ceased)
Field Capacity (%)
0
20
40
60
80
100
Sand
Sandy Loam
Silt Loam
Clay
Question 4. According to Figure 2, which of the following correctly ranks the four soil types from lowest to highest field capacity?
-
A) Clay, Silt Loam, Sandy Loam, Sand
-
B) Sand, Sandy Loam, Silt Loam, Clay ✓
-
C) Sand, Silt Loam, Sandy Loam, Clay
-
D) Sandy Loam, Sand, Clay, Silt Loam
Explanation: Reading the bar heights in Figure 2 from shortest to tallest: Sand (~15%) has the lowest field capacity, followed by Sandy Loam (~28%), then Silt Loam (~50%), and Clay (~55%) with the highest. This reflects the role of particle size, smaller clay particles create greater surface area and smaller pores that hold water more tightly against gravity, while large sand pores drain almost completely. Note that Silt Loam and Clay are relatively close in field capacity, but Clay's smaller pores retain slightly more water after drainage.
Figure 1
Soil scientists investigated how soil texture affects water retention and drainage. Four soil types; Sand, Sandy Loam, Silt Loam, and Clay, were each packed into identical 30 cm columns with sealed bottoms fitted with drainage valves. Each column was saturated with 500 mL of distilled water, and the valve was opened simultaneously for all columns. The volume of water drained (in mL) was recorded at 10-minute intervals for 60 minutes (Figure 1). After 60 minutes, the researchers measured the field capacity of each soil type, the percentage of total pore space remaining filled with water after free drainage had ceased (Figure 2).
Figure 1. Cumulative Water Drained vs. Time
Water Drained (mL)
Time (min)
0
100
200
300
400
500
10
20
30
40
50
60
Sand
Sandy Loam
Silt Loam
Clay
Question 5. The drainage rate of a soil is defined as the change in volume drained per unit time. Based on Figure 1, during which time interval did the Sand column have the highest drainage rate?
-
A) 0 to 10 minutes ✓
-
B) 10 to 20 minutes
-
C) 20 to 30 minutes
-
D) 40 to 50 minutes
Explanation: Drainage rate equals the slope of the cumulative drainage curve, steeper slope means faster drainage. For Sand (blue line), the steepest portion occurs from 0 to 10 minutes, where approximately 420 mL drained in just 10 minutes (~42 mL/min). Every subsequent interval shows a much shallower slope as the largest pores empty first and drainage slows considerably. This is consistent with how sandy soils behave: extremely rapid initial drainage as gravity quickly empties the large pores, followed by near-complete drainage within 20–30 minutes.