Depending on their age, a person needs 7–17 hours sleep in every 24 hours. But, just sleeping is not enough. Deep sleep is essential for health and wellbeing. Most adults need around 1.5–2 hours of ...

Once raw data has been collected, you need to represent it in a diagram. Two ways of doing this are to use a pie chart or frequency diagram. In a survey, 100 school students were asked to name their ...