Measures of central tendency


Add all the measurements together then divide by the number of measurements taken.


Arrange the data in order and take the middle value as the median.


The value which occurs most often.

Measures of dispersion


The spread of data around the average.


Range is the distance between the highest and lowest value.

Example: 12 17 21 23 24 24 25 26 29 31
Range = 12–31

Interquartile range is the part of the range that covers the middle 50% of the data.

Secondary and Further Education Courses

Set your students up for success with our secondary school trips and courses. Offering excellent first hand experiences for your students, all linked to the curriculum.
People forraging in Tollymore

Group Leader and Teacher Training

Centre-based and digital courses for teachers

Experiences for Young People

Do you enjoy the natural world and being outdoors? Opportunities for Young People aged 16-25.
Lady with laptop in mountainous area

Digital Hub Plus

Subscribe/login to our package of teaching videos and resources