Head Start to A-Level Maths: Statistics and Probability 0.0 / 5 ? MathematicsProbabilityA2/A-levelEdexcel Created by: Jamie HallCreated on: 24-08-20 08:53 What is the population? The population is the whole group you want to investigate. 1 of 25 Wha is a census? If you collect information from every single member of the population 2 of 25 What is a sample? A selection from the population to represent the whole group. 3 of 25 How can you obtain reliable results from a sampling frame? The sampling fame should include as much of the population as possible. 4 of 25 How can you limit bias as much as possible? • Choose from the correct population and don’t exclude anyone. • Choose your sample at random. • Make sure your sample is big enough. 5 of 25 What is the Simple Random Sampling method? It gives every member of the population an equal chance of being in the sample, so it's unbiased. 6 of 25 How to select a Simple Random Sample? Start by giving every member of the population a unique number. Then generate a list of random numbers and match them to the population members. 7 of 25 What is a variable? A quantity that can take different values. 8 of 25 What are qualitative variables? They take non-numerical values – e.g. colours of cars. 9 of 25 What are quantitative variables? They take numerical values – e.g. temperature. 10 of 25 What are the different types of quantitative data? Discrete and Continuous 11 of 25 What are discrete variables? They take certain values within a particular range – e.g. shoe size. 12 of 25 What are continuous variables? They take any value within a particular range – e.g. length. 13 of 25 What is the formula for class width? Upper class boundary - Lower class boundary 14 of 25 What is the formula for a histogram? Frequency = Frequency Density x Class Width 15 of 25 How to find the modal class in grouped data? The modal class is the class with the highest frequency density. 16 of 25 How to estimate the mean in grouped data? To estimate the mean, you’ll need to add extra columns – one for the mid-point of each class and another for Frequency x Mid-point. 17 of 25 What are outcomes? The different things that can happen in a probability experiment. 18 of 25 What is an event? The thing you want to find the probability of. 19 of 25 What is the formula you can use to work out the probability of an event when all the possible outcomes are equally likely? P(event) = Number of outcomes where event happens / Total number of possible outcomes. 20 of 25 How do you calculate the expected frequency of a result? Expected frequency of a result = Probability x Number of Trials 21 of 25 What is the universal set? Is the group of things that the elements of the sets are selected from. It’s everything inside the rectangle. 22 of 25 What is the union? The union of sets A and B, ( A U B), contains all elements in either set A or set B. It’s everything inside the circles. 23 of 25 What is the intersection? The intersection of sets A and B, (A n B), contains all the elements in both set A and set B. It’s where the circles overlap. 24 of 25 What is the complement? The complement of set A, (A’), contains all members of the universal set that aren’t in set A. 25 of 25

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