TRI DUC ENGLISH ✦ ACADEMIC EDGE UNIT 26 EDITION Statistics Statistical terms · Probability problems · Analyzing data sets 💡 Pro Tip: Di chuột (hover) vào các từ in đậm màu cam trong phần lý thuyết để xem định nghĩa chi tiết. A. Basic statistical terms A normal distribution of data means that most of the examples in a set of data are close to the average, while relatively few examples tend to one extreme or the other . Normally distributed data shown on a chart will typically show a bell curve .   It will often be necessary to work out the extent to which individuals deviate from the norm and to calculate the figure that represent standard deviation . Six children are 7, 8, 8, 8, 11 and 12 years old . Their average age is 9 years old (the sum of their ages divided by six) . The mode (the most frequent value) is 8 . The median is 9.5 (the halfway point between the two extremes of the range) . Statisticians are often concerned with working out correlation — the extent to which, say, left-handedness correlates with intelligence . They must ensure that any data they collect is valid , i.e. that it is measuring what it claims to measure - all the subjects in the sample must be appropriately and accurately assessed . The figures must also be reliable , i.e. they would be consistent if the measurements were repeated . Usually, statisticians hope that their calculations will show/indicate a tendency , e.g that left-handed people will be shown to be significantly more intelligent than right-handed people . B. A probability problem Sue picks a card at random from an ordinary pack of 52 cards . If the card is a king, she stops . If not, she continues to pick cards at random, without replacing them, until either a king is picked or six cards have been picked . The random variable , C, is the total number of cards picked . Constru...