Data Representation

ACT Science Data Analysis

Part 1 of 7 — Trends in tables and graphs

Most ACT Science questions in this unit are solved with arithmetic and careful reading of labels. Use this sequence:

1. Identify variable on each axis.
2. Compute only what the question asks (difference, rate, or estimate).
3. Match units before finalizing.

Precision beats speed-reading in data-heavy passages.

Data Fundamentals

Worked Numeric Example

A table lists concentration (mM) and absorbance:

• 2 mM → 0.18
• 4 mM → 0.33
• 6 mM → 0.47

Suppose a question asks for the estimated absorbance at 5 mM. 5 mM lies between 4 and 6 mM, so interpolate between 0.33 and 0.47. Midpoint estimate: about 0.40.

On ACT Science, interpolation is usually linear unless the graph clearly curves.

Computation Set

1. A value rises from 14 to 23. Enter the increase.
2. A quantity changes from 50 to 65 over 3 minutes. Enter average rate per minute (decimal allowed).
3. If a point estimate is 31 and measured value is 28, enter absolute error.

Practical Strategy for Trends in tables and graphs

• When options are close, compute with one extra decimal before choosing.
• For controls/variables items, identify what is held constant first.
• For uncertainty questions, overlapping error bars mean weak evidence for a difference.
• In synthesis passages, build a mini two-column note: Source A claim vs Source B claim.

Reasoning Match

Timed Review Questions

ACT Science Data Analysis

Part 2 of 7 — Interpolation and extrapolation

Most ACT Science questions in this unit are solved with arithmetic and careful reading of labels. Use this sequence:

1. Identify variable on each axis.
2. Compute only what the question asks (difference, rate, or estimate).
3. Match units before finalizing.

Precision beats speed-reading in data-heavy passages.

Data Fundamentals

Worked Numeric Example

A table lists concentration (mM) and absorbance:

• 2 mM → 0.18
• 4 mM → 0.33
• 6 mM → 0.47

Suppose a question asks for the estimated absorbance at 5 mM. 5 mM lies between 4 and 6 mM, so interpolate between 0.33 and 0.47. Midpoint estimate: about 0.40.

On ACT Science, interpolation is usually linear unless the graph clearly curves.

Computation Set

1. A value rises from 14 to 23. Enter the increase.
2. A quantity changes from 50 to 65 over 3 minutes. Enter average rate per minute (decimal allowed).
3. If a point estimate is 31 and measured value is 28, enter absolute error.

Practical Strategy for Interpolation and extrapolation

• When options are close, compute with one extra decimal before choosing.
• For controls/variables items, identify what is held constant first.
• For uncertainty questions, overlapping error bars mean weak evidence for a difference.
• In synthesis passages, build a mini two-column note: Source A claim vs Source B claim.

Reasoning Match

Timed Review Questions

ACT Science Data Analysis

Part 3 of 7 — Rates and slopes

Most ACT Science questions in this unit are solved with arithmetic and careful reading of labels. Use this sequence:

1. Identify variable on each axis.
2. Compute only what the question asks (difference, rate, or estimate).
3. Match units before finalizing.

Precision beats speed-reading in data-heavy passages.

Data Fundamentals

Worked Numeric Example

A table lists concentration (mM) and absorbance:

• 2 mM → 0.18
• 4 mM → 0.33
• 6 mM → 0.47

Suppose a question asks for the estimated absorbance at 5 mM. 5 mM lies between 4 and 6 mM, so interpolate between 0.33 and 0.47. Midpoint estimate: about 0.40.

On ACT Science, interpolation is usually linear unless the graph clearly curves.

Computation Set

1. A value rises from 14 to 23. Enter the increase.
2. A quantity changes from 50 to 65 over 3 minutes. Enter average rate per minute (decimal allowed).
3. If a point estimate is 31 and measured value is 28, enter absolute error.

Practical Strategy for Rates and slopes

• When options are close, compute with one extra decimal before choosing.
• For controls/variables items, identify what is held constant first.
• For uncertainty questions, overlapping error bars mean weak evidence for a difference.
• In synthesis passages, build a mini two-column note: Source A claim vs Source B claim.

Reasoning Match

Timed Review Questions

ACT Science Data Analysis

Part 4 of 7 — Controls and variables

Most ACT Science questions in this unit are solved with arithmetic and careful reading of labels. Use this sequence:

1. Identify variable on each axis.
2. Compute only what the question asks (difference, rate, or estimate).
3. Match units before finalizing.

Precision beats speed-reading in data-heavy passages.

Data Fundamentals

Worked Numeric Example

A table lists concentration (mM) and absorbance:

• 2 mM → 0.18
• 4 mM → 0.33
• 6 mM → 0.47

Suppose a question asks for the estimated absorbance at 5 mM. 5 mM lies between 4 and 6 mM, so interpolate between 0.33 and 0.47. Midpoint estimate: about 0.40.

On ACT Science, interpolation is usually linear unless the graph clearly curves.

Computation Set

1. A value rises from 14 to 23. Enter the increase.
2. A quantity changes from 50 to 65 over 3 minutes. Enter average rate per minute (decimal allowed).
3. If a point estimate is 31 and measured value is 28, enter absolute error.

Practical Strategy for Controls and variables

• When options are close, compute with one extra decimal before choosing.
• For controls/variables items, identify what is held constant first.
• For uncertainty questions, overlapping error bars mean weak evidence for a difference.
• In synthesis passages, build a mini two-column note: Source A claim vs Source B claim.

Reasoning Match

Timed Review Questions

ACT Science Data Analysis

Part 5 of 7 — Uncertainty and error bars

Most ACT Science questions in this unit are solved with arithmetic and careful reading of labels. Use this sequence:

1. Identify variable on each axis.
2. Compute only what the question asks (difference, rate, or estimate).
3. Match units before finalizing.

Precision beats speed-reading in data-heavy passages.

Data Fundamentals

Worked Numeric Example

A table lists concentration (mM) and absorbance:

• 2 mM → 0.18
• 4 mM → 0.33
• 6 mM → 0.47

Suppose a question asks for the estimated absorbance at 5 mM. 5 mM lies between 4 and 6 mM, so interpolate between 0.33 and 0.47. Midpoint estimate: about 0.40.

On ACT Science, interpolation is usually linear unless the graph clearly curves.

Computation Set

1. A value rises from 14 to 23. Enter the increase.
2. A quantity changes from 50 to 65 over 3 minutes. Enter average rate per minute (decimal allowed).
3. If a point estimate is 31 and measured value is 28, enter absolute error.

Practical Strategy for Uncertainty and error bars

• When options are close, compute with one extra decimal before choosing.
• For controls/variables items, identify what is held constant first.
• For uncertainty questions, overlapping error bars mean weak evidence for a difference.
• In synthesis passages, build a mini two-column note: Source A claim vs Source B claim.

Reasoning Match

Timed Review Questions

ACT Science Data Analysis

Part 6 of 7 — Data synthesis across figures

Most ACT Science questions in this unit are solved with arithmetic and careful reading of labels. Use this sequence:

1. Identify variable on each axis.
2. Compute only what the question asks (difference, rate, or estimate).
3. Match units before finalizing.

Precision beats speed-reading in data-heavy passages.

Data Fundamentals

Worked Numeric Example

A table lists concentration (mM) and absorbance:

• 2 mM → 0.18
• 4 mM → 0.33
• 6 mM → 0.47

Suppose a question asks for the estimated absorbance at 5 mM. 5 mM lies between 4 and 6 mM, so interpolate between 0.33 and 0.47. Midpoint estimate: about 0.40.

On ACT Science, interpolation is usually linear unless the graph clearly curves.

Computation Set

1. A value rises from 14 to 23. Enter the increase.
2. A quantity changes from 50 to 65 over 3 minutes. Enter average rate per minute (decimal allowed).
3. If a point estimate is 31 and measured value is 28, enter absolute error.

Practical Strategy for Data synthesis across figures

• When options are close, compute with one extra decimal before choosing.
• For controls/variables items, identify what is held constant first.
• For uncertainty questions, overlapping error bars mean weak evidence for a difference.
• In synthesis passages, build a mini two-column note: Source A claim vs Source B claim.

Reasoning Match

Timed Review Questions

ACT Science Data Analysis

Part 7 of 7 — Mixed review with timed sets

Most ACT Science questions in this unit are solved with arithmetic and careful reading of labels. Use this sequence:

1. Identify variable on each axis.
2. Compute only what the question asks (difference, rate, or estimate).
3. Match units before finalizing.

Precision beats speed-reading in data-heavy passages.

Data Fundamentals

Worked Numeric Example

A table lists concentration (mM) and absorbance:

• 2 mM → 0.18
• 4 mM → 0.33
• 6 mM → 0.47

Suppose a question asks for the estimated absorbance at 5 mM. 5 mM lies between 4 and 6 mM, so interpolate between 0.33 and 0.47. Midpoint estimate: about 0.40.

On ACT Science, interpolation is usually linear unless the graph clearly curves.

Computation Set

1. A value rises from 14 to 23. Enter the increase.
2. A quantity changes from 50 to 65 over 3 minutes. Enter average rate per minute (decimal allowed).
3. If a point estimate is 31 and measured value is 28, enter absolute error.

Practical Strategy for Mixed review with timed sets

• When options are close, compute with one extra decimal before choosing.
• For controls/variables items, identify what is held constant first.
• For uncertainty questions, overlapping error bars mean weak evidence for a difference.
• In synthesis passages, build a mini two-column note: Source A claim vs Source B claim.

Reasoning Match

Timed Review Questions