A lot of people use the equals sign wrongly in places where another word or phrase might actually make the meaning clearer. Sometimes a link word or phrase is useful at the beginning of a mathematical sentence: examples include ‘So’, ‘This implies’ or ‘It follows that’ or ‘Hence’.

## Example 3

Author(s): The Open University

The interquartile range is a useful measure of dispersion in the data and it has the excellent property of not being too sensitive to outlying data values. (That is, it is a resistant measure.) However, like the median it does suffer from the disadvantage that its calculation involves sorting the data. This can be very time-consuming for large samples when a computer is not available to do the calculations. A measure that does not require sorting of the data and, as you will find in later uni
Author(s): The Open University

Everyone professes to understand what is meant by the term ‘average’, in that it should be representative of a group of objects. The objects may well be numbers from, say, a batch or sample of measurements, in which case the average should be a number which in some way characterises the batch as a whole. For example, the statement ‘a typical adult female in Britain is 160 cm tall’ would be understood by most people who heard it. Obviously not all adult females in Britain are the same
Author(s): The Open University

Histograms provide a quick way of looking at data sets, but they lose sight of individual observations and they tend to play down ‘intuitive feel’ for the magnitude of the numbers themselves. We may often want to summarize the data in numerical terms; for example, we could use a number to summarize the general level (or location) of the values and, perhaps, another number to indicate how spread out or dispersed they are. In this section you will learn about some numerical summaries
Author(s): The Open University

It is a fundamental principle in modern practical data analysis that all investigations should begin, wherever possible, with one or more suitable diagrams of the data. Such displays should certainly show overall patterns or trends, and should also be capable of isolating unexpected features that might otherwise be missed. The histogram is a commonly-used display, which is useful for identifying characteristics of a data set. To illustrate its use, we return to the data set on infants with SI
Author(s): The Open University

Electric Eddy and the Return of the Prodigal Son
Eddy and Delta discover how energy inefficient a young student can be. But what would it takes to make him more environmentally aware? (02:13)

Author(s): No creator set

China - Economic Miracle or Economic Timebomb?
The growth of China in recent years has been described as an economic miracle with Western companies and governments rushing to build partnerships with the new power in the East. The opening up of the Chinese market and the expansion of industry, technology and production within the country has, however, had a profound effect on the people of China, its political leaders and the rest of the world. This impact can be seen in the growing inequalities within China, the loss of jobs in the west a
Author(s): No creator set

French Lesson - Dans la Ville (In the City), Part 9
Learn French by learning vocabulary words for buildings in the city. As the native French speaker recites the words, the words and the appropriate images appear. There is no English spoken. Each French phrase is spoken once. For beginning to intermediate learners. This video features a picture within the picture, so the viewer may want to open the video to 'full screen' to see the smaller image
Author(s): No creator set

Digital Library Object - Graphics-oriented battlefield tracking systems: U.S. Army and Air Force int
Author(s): No creator set

Sixty-five million years ago, animal and plant life were very different from nowadays, but there were rat-sized placental mammals living successfully on the ground. They were insect eaters, i.e. insectivores, feeding on the vast numbers of insects and other invertebrates living in soil, leaf litter and low-lying vegetation. Insectivore means 'insect eater', and in this course we will explore the world of insect-eating mammals, classified together on the basis of a reasonably close evolutionar
Author(s): The Open University

Studying mammals: Food for thought
Who were our ancestors? How are apes and humans related? And where does the extinct Homo erectus fit into the puzzle? In this free course, Studying mammals: Food for thought, we will examine culture, tool use and social structure in both apes and humans to gain an understanding of where we come from and why we behave as we do. This is the tenth course in the Studying mammals series.Author(s): Creator not set

In this , we describe the theory of evolution by natural selection as proposed by Charles Darwin in his book, first published in 1859, On The Origin of Species by Means of Natural Selection, or The Preservation of Favoured Races in the Struggle for Life. We will look at natural selection as Darwin did, taking inheritance for granted, but ignoring the mechanisms underlying it.

This OpenLearn course provides a sample of level 1 study in
Author(s): The Open University

This course is the first in a series of three on Animals at the extreme. It is concerned with the integration of behaviour anatomy, physiology and biochemistry in diverse vertebrates that live in deserts. Once you have completed this course, you will be all the more able to appreciate the linked courses that follow, Animals at the extreme: hibernation and torpor and Animals at the extreme: the polar environment. These courses build on and develop some of the science you w
Author(s): The Open University

This course is an introduction to chemistry concepts, using water as the main illustration. Much of the course is devoted to exploring the smallest water particle - a water molecule - what it is and how it gives rise to the particular properties of water. The course also explains powers of ten and scientific notation, which are a convenient way of expressing both very large and very small numbers. It is a good introduction to science.

This OpenLearn course provides a sample of level 1 s
Author(s): The Open University

In this course, we will examine the biology of the impressive meat eaters (e.g. wolves, lions and cheetahs), focusing in part on the biological 'equipment' - slashing and gripping teeth, for example - and on the less obvious behavioural characteristics that have contributed to the undoubted success of these fearsome hunters. Many of the meat eaters live and hunt in groups, which raises intriguing questions about the advantages of group living and the types of social behaviour between individu
Author(s): The Open University

The plant predators, or herbivores, are a varied group, but they share certain characteristics. Many of them are large; among the smallest is the chevrotain (or mouse-deer) at about two kilograms weight, and the elephant is the largest, with a typical bull male weighing around six tonnes. In this course we'll be looking in more detail at some of the problems and consequences of adopting a plant-eating way of life. Leaves are a much less nutritious food than most kinds of animal material, so l
Author(s): The Open University

Mammals come in a bewildering variety of shapes and sizes and yet all of the 4700 or so species have some characteristics in common. Indeed, it's the existence of these common features that justifies the inclusion of all such diverse types within the single taxonomic group (or class) called the Mammalia.

This is the first in a series of units about studying mammals. To get the most from these units, you will need access to a copy of The Life of Mammals (2002) by David Attenboroug
Author(s): The Open University

All of the animals described in this course are members of the mammalian order Rodentia. The rodents are widely regarded as amongst the most successful of all the mammalian groups. We will examine some features of rodent biology that contribute to their success, in particular their exploitation of a unique range of plant foods, especially seeds, wood and roots. While focusing on rodent feeding behaviour and reproduction, we will also be exploring some more general ideas concerning the origin
Author(s): The Open University

This course explores the topic of climate change and global warming. We will begin by exploring how the Earth's global mean surface temperature is determined through a global “balancing act” of the rate of energy that comes from the Sun and the rate at which the planet returns that energy into space. We will also discuss the natural greenhouse effect, and how this contributes to a balanced global climate. We will then go on to consider the human impact on the atmosphere, including the imp
Author(s): The Open University

This course will allow you to extend your visual modelling skills through the use of the sign graph diagramming technique. You will explore the dynamic relationship between social, economic and ecological factors whose interdependencies will determine the complex dynamics of the future as it unfolds. Your final task will be to identify points of intervention within this complex system in order to "nudge" the situation towards a more favourable outcome.

This OpenLearn course provides a s
Author(s): The Open University