# Numerical and Statistical Skills Flashcards

1️⃣ Familiarise yourself with the flashcards:

• Look through all the flashcards to see what’s on both sides.
• Make sure you understand the information on each card. If something’s unclear, click the link to the revision notes at the bottom of the page for more details.

2️⃣ Test yourself:

• Look at the question or prompt on each card and try to remember the answer before flipping it over.
• Check the answer and make a note of any cards you find challenging and need to go over more.

3️⃣ Consistently Review and Practice:

• Use spaced repetition: spend more time on the cards you struggle with and go over them more often.
• Regularly review all the flashcards to help you better understand and retain the information over time.

Note: We may include questions that have multiple correct answers. It’s useful to remember specific examples to understand these concepts better.

## What is the range in a dataset?

The range is the difference between the highest and lowest values in a dataset. It indicates the spread within the data.

Calculation: Highest value – Lowest value

## How do you calculate the mean of a dataset?

The mean is calculated by dividing the sum of all values in a dataset by the number of values.

Calculation: Sum of values ÷ Number of values

## What is the median in a dataset?

The median is the middle value in an ordered dataset, dividing it into two halves.

Example: For the dataset 7, 9, 10, 15, 17, 22, 29, 31, 40, the median is 17.

## How do you determine the mode of a dataset?

The mode is the most frequently occurring value in a dataset.

Example: In the dataset 7, 9, 10, 15, 15, 17, 22, 22, 22, 26, 26, 29, 31, 40, the mode is 22.

## What are quartiles in a dataset?

Quartiles divide a dataset into four equal parts. Q1 is the median of the lower half, Q2 is the median of the dataset, and Q3 is the median of the upper half.

## How do you calculate percentage change?

Percentage change is calculated by determining the difference between two numbers, dividing by the original number, and then multiplying by 100.

Calculation:
(Difference ÷ Original number) × 100