Home of real teaching & learning
  • Full support for teachers
  • Focus on critical thinking
  • Engaging classroom activities
  • Integrated student eBook
  • Assessed tasks / qBank
  • Practice exam questions
Find out more Download brochure

The InThinking Guarantee: Our sites are written by expert practitioners and not by AI

See our AI policy

Disclaimer: InThinking subject sites are neither endorsed by nor connected with the International Baccalaureate Organisation.

Don't miss out, find out!

Practising Data & Stats Skills - Phosphorous in Mud

This activity allows you to practice your data and statistics skills by graphing and analysing some data on mud. Answers can be found here: Practising Data & Stats Skills - Phosphorous in Mud (Answers) 

Mud matters! That mucky, (sometimes) stinky stuff is a dynamic environment with two key functions:

  • A home for microbes: Mud is teeming with microbes that decompose, or break down, dead plant and animal material to get energy.
  • A source of nutrients: It is often rich in the element phosphorus, which acts as a natural fertiliser for plants in the ecosystem.

But no two patches of mud are the same. In this activity, we'll dive into some data to see if there's a difference in the phosphorus levels of mud collected from a lake and a wetland area. 

The process was simple: collect the mud, dry it out completely, and then measure the amount of phosphorus. NOTE: Phosphorus is reported in ug P/g d.w. which means “micrograms of Phosphorus per gram of dry weight.”

Table 1: Data on phosphorus collected from a lake (10 different locations) and a wetland area (10 different locations).

Lake Location

Total Phosphorus (ug P/g dw)

Wetland Location

Total Phosphorus 
(ug P/g dw)

# 1

528

# 1

773

# 2

523

# 2

1687

# 3

105

# 3

167

# 4

25

# 4

459

# 5

204

# 5

1909

# 6

556

# 6

443

# 7

512

# 7

130

# 8

490

# 8

1574

# 9

366

# 9

1604

# 10

177

# 10

1387

The data is also available in this SPREADSHEET.

NOTE: Ideally you would have more data than given here. This data set has been chosen to allow you to practice calculations easily.

PART 1: Looking at raw data

1. To begin to understand what the data reveals in relation to the research question, draw an appropriate graph of the raw data. NOTE: This graph wouldn't necessarily appear in an IA but rather helps you begin to understand your data.

2. Explain what your graph reveals about the raw data.

PART 2: Processing data

3. Calculate the mean and standard deviation for each location.

4. This processed data can be graphed as shown below. Explain what the processed data reveals.

PART 3: Analysing your data using statistical tests

5. Describe how you would proceed from here to analyse the data further. Consider:
    - What is the goal − to compare variables or find a relationship between variables?
    - What is the most appropriate statistical test?
    - What would be the testing hypotheses?
    - Carry out the test and write up the results.

   The image below may be helpful.

All materials on this website are for the exclusive use of teachers and students at subscribing schools for the period of their subscription. Any unauthorised copying or posting of materials on other websites is an infringement of our copyright and could result in your account being blocked and legal action being taken against you.

Help