Tables, Graphs & Patterns in Data — Practice · Grade 7 Science

Chapter: Scientific Inquiry & Diversity of Life

What this practice covers

By the end of Tables, Graphs & Patterns in Data you should be able to:

8 questions, written answer, multiple choice and numeric, each with a worked explanation.

Vocabulary used: data, mean, range, correlation, extrapolation.

Problem 1

Why is a missing measurement not automatically zero?
Answer and explanation

Missing means no valid observation was recorded. Zero claims that the measured quantity was actually zero.

Problem 2

How can uneven time spacing mislead a reader?
Answer and explanation

It can make the same change appear faster or slower because equal horizontal distances no longer represent equal times.

Problem 3

Does a mean of 5 cm require each plant to be 5 cm?
Answer and explanation

No. Different combinations of measurements can average 5 cm. Inspect the original values and their spread.

Problem 4

Why is extending a seven-day growth line to a year uncertain?
Answer and explanation

The extension assumes the same growth rate and conditions far beyond the measured interval; resource limits and development can change the pattern.

Problem 5

Illustrative records: Treatment A height gains are 3, 4, and 5 cm; B gains are 1, 4, and 7 cm under the same stated interval. Calculate the means and numerical ranges. Describe one similarity, one difference, and what the summaries cannot establish.
Answer and explanation

Both means are 4 cm. A’s numerical range is 2 cm; B’s is 6 cm. The means agree but B’s observations are more spread out. These small illustrative sets do not establish why variability differs or whether a treatment caused the pattern. Keep individual records, examine methods, and use more independent observations.

A sum is 12 cm and B sum is 12 cm.

Divide each by three.

Subtract smallest from largest in each set.

Compare spread without inventing a cause.

Response criteria

  • Explain the relevant biological process accurately.
  • Use the supplied evidence and show calculation steps with units where needed.
  • Connect a labeled model or mechanism with the claim.
  • State an assumption, evidence limitation, or useful next observation.

Problem 6

A graph shows an association between rainfall and plant height. Does the association alone prove rainfall caused every difference?
Answer and explanation

No. Other conditions such as soil, species, light, and initial size may differ. A causal explanation needs a plausible mechanism and comparisons addressing alternatives.

Response criteria

  • Explain the relevant biological process accurately.
  • Use the supplied evidence and show calculation steps with units where needed.
  • Connect a labeled model or mechanism with the claim.
  • State an assumption, evidence limitation, or useful next observation.

Problem 7

Which graph is suitable for separate habitat categories?
  1. A bar graph
  2. A drawing without labels
  3. A graph with changing scale intervals
  4. A pie chart with no totals
Answer and explanation

A bar graph

Bars can compare separate habitat categories when units and sampling effort are comparable.

Problem 8

Find the mean of 2, 4, and 9 cm.
Answer and explanation

5 cm

(2+4+9)/3=15/3=5 cm.

Browse all courses