Percentage change, ratios & rate from graphs
Practice Flashcards
Flip to reveal answersFormula: percentage change
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 6 Flashcards — Percentage change, ratios & rate from graphs
Sign up free to track progress and get spaced-repetition review schedules.
Question
Formula: percentage change
Answer
$\% \text{ change} = \dfrac{\text{new} - \text{old}}{\text{old}} \times 100$ — always divide the CHANGE by the OLD value. A negative answer is a percentage decrease.
Question
Formula: rate from a graph
Answer
rate $= \dfrac{\text{change in quantity}}{\text{time}} = \dfrac{\text{rise}}{\text{run}}$ — the GRADIENT of the line. Take two points and divide; always write the units.
Question
Formula: ratio / index
Answer
ratio = part ÷ whole, e.g. mitotic index $= \dfrac{\text{dividing cells}}{\text{total cells}}$. Can be a fraction, decimal, percentage or A : B.
Question
Percentage change vs 'percentage of'
Answer
**% change** = (new − old) ÷ old × 100 (how much it moved). **% of** = part ÷ whole × 100 (what share it is). Read which one the question asks.
Question
How do you find the range of a data set?
Answer
range = largest value − smallest value.
Question
Why must a rate have units?
Answer
A rate is a quantity PER unit time; without the unit (e.g. cm³ s⁻¹, breaths min⁻¹) it is incomplete and loses the mark.
Read the notes
Full study notes for Percentage change, ratios & rate from graphs
Topic 5.1 hub
Experimental and data skills
More from Topic 5.1
All flashcards in this topic
Biology exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free