Complete stratified sampling lesson made for my year 10, top set, gcse class. Use a stratified sampling method to calculate how many people from each country should invited to the conference an international festival is to held, but tickets are limited to 50. Systematic sampling has slightly variation from simple random sampling. This was taken from my 150 page workbook which covers many more maths topics. To download this file, click the button below to signup it only takes a minute and youll be brought right back to this page to start the download. Click here for questions click here for answers sample. Gcse statistics revision notes collecting data sample this is. Aug 27, 2012 the corbettmaths video tutorial on stratified sampling. Unlike the simple random sample and the systematic random sample, sometimes we are interested in particular strata meaning groups within the population e.
Apr, 2019 stratified random sampling provides the benefit of a more accurate sampling of a population, but can be disadvantageous when researchers cant classify every member of the population into a subgroup. Gcse maths revision stratified sampling teaching resources. In what follows, the application of stratified sampling in mc yield estimation will be discussed. Stratified sampling practice questions corbettmaths. Proportionate allocation uses a sampling fraction in each of the strata that is proportional to that of the total population. Learn about and revise how to use questionnaires and data collection sheets correctly with gcse bitesize maths. Stratified random sampling definition investopedia. The company has 4 largeload vehicles, 6 light vans and 21 cars. Hence, there is a same sampling fraction between the strata. For example, if a class has 20 students, 18 male and 2 female, and a researcher wanted a sample of 10, the sample would consist of 9 randomly chosen males and 1 randomly chosen. Stratified random sampling provides the benefit of a more accurate sampling of a population, but can be disadvantageous when researchers cant classify every member of the population into a subgroup. Random and stratified sampling questions, worksheets. He decides to ask a stratified sample of 50 students. Jan 27, 2020 a stratified sample can also be smaller in size than simple random samples, which can save a lot of time, money, and effort for the researchers.
The table shows the number of students who study each of these languages. Sampling is the process of looking at a small selection of peopleobjects from a wider population in order to learn new information about that population. In order to fully understand stratified sampling, its important to be. Maths revision video and notes on the topic of stratified sampling. Stratified sampling higher collecting data ccea gcse. Accordingly, the quota is based on the proportion of subclasses in the population. Random and stratified sampling this lesson can be used for revision for the higher maths gcse.
I hope the video helps and please do leave a comment thanks. Students learn the difference between different types of sampling methods and how to calculate a stratified sample size using equal proportions. The population is classified by age as shown in the table below. In taking a sample of villages from a big state, it is more administratively convenient to consider the districts as strata so that the administrative set up at district level may be used. As learning progresses students are challenged to work the problem in reverse by finding the population of each strata given the sampling size. By separating the population into groups age groups, genders, etc.
For example, an urban ward may contain 8 deprived wards and 2 undeprived wards. Jul 24, 2018 a gcse maths worksheet covering stratified sampling. Data collection and sampling edexcel gcse geography revision. Here only the first sampling unit is selected at random and the remaining units are automatically selected in a definite sequence at equal intervals. Edexcel gcse maths linear 1ma0 stratified sampling answers. To do this, you might ask 500 people from the uk how many books they finished last year this is a sample.
For example, suppose you want to know about reading habits in the uk. Data collection sheets should have a simple design so that the results are clear to read. This is because this type of sampling technique has a high statistical precision compared to simple random sampling. Stratified sampling practice questions click here for questions. If the groups are of different sizes, the number of items selected from each group will be proportional. Stratified sampling is a process used in market research that involves dividing the population of interest into smaller groups, called strata.
The inspector decides to sample 10% of the vehicles. Calculate the number of people that should be sampled from each age. Stratified sampling is a method we can use to make our sample more representative. The main things to remember when working with gcse mathematics stratified sampling questions are. Lesson includes definition and builds the difficulty of examples which my class found insightful. Covers all parts of the gcse syllabus, including sampling methods random and stratified sampling. Jan 06, 2016 stratified sampling deals mainly with fractions and is usually on a gcse calculator question paper. In stratified random sampling or stratification, the strata.
Random sampling, stratified sampling, systematic sampling, cluster sampling, quota sampling. Gcse revision video 31 stratified sampling youtube. A study of stratified sampling in variance reduction. Chapter 5 choosing the type of probability sampling 1 stratified sampling what is stratified sampling. Each student studies one of greek or spanish or german or french. This is when the population is split into could have sub groups. Administrative convenience can be exercised in stratified sampling.
Understanding stratified samples and how to make them. Stratified sampling questions worksheets and revision mme. Stratified sampling is used to select a sample that is representative of different groups. Check that you know the total population size this. Stratified sampling is when the population can be classified into groups or strata. A gcse maths worksheet covering stratified sampling. Updated for the 2012 exam ultimate gcse statistics. Stratified sampling is a sampling technique where the researcher divides or stratifies the target group into sections, each representing a key group or characteristic that should be present in the final sample.
Having overlapping subgroups will grant some individuals higher chances of being selected as subject. All the sampling units drawn from each stratum will constitute a stratified sample of size 1. Each type of vehicle is to be represented in the sample. Gcse mathematics stratified sampling 3 minute maths. The main difference between quota and stratified sampling can be explained in a way that in quota sampling researchers use nonrandom sampling methods to gather data from one stratum until the required quota fixed by the researcher is fulfilled. Suitable for all the big examination boards including aqa, edexcel, ocr and wjec.
Stratified random sampling is a method of sampling that involves the division of a population into smaller groups known as strata. Edexcel gcse mathematics linear 1ma0 stratified sampling materials required for examination items included with question papers ruler graduated in centimetres and nil millimetres, protractor, compasses, pen, hb pencil, eraser. Stratified sampling definition of stratified sampling by. A headteacher wants to find out what year 7 think about their first term at their new school.
Select a sample stratified by one category and by more than one category. A worksheet and exam style practice questions covering gcse stratified sampling. Sampling theory chapter 4 stratified sampling shalabh, iit kanpur page 7 3. He wants to find out how often people have been to the library in the last year. Stratified sampling higher collecting data ccea gcse maths. What is the difference between systematic sampling and. Stratified sampling is a probability sampling procedure in which the target population is first separated into mutually exclusive, homogeneous segments strata, and then a simple random sample is selected from each segment stratum.
Stratified random sampling intends to guarantee that the sample represents specific subgroups or strata. Other results for edexcel gcse maths linear 1ma0 stratified sampling answers. In a stratified sample, the proportion of each group is the same as the proportion in the whole population. If the groups are of different sizes, the number of items selected from. Updated for the 2012 exam ultimate gcse statistics revision guide. Gcse 91 statistics and order your free evaluation pack at. Suitable for gcse students sitting the 9 1, alevel maths students revision and some key stage 3 students. Want to download the sampling revision notes in pdf format. Stratified random sampling is a method of sampling that involves the division of a population into smaller subgroups known as strata. Total sample size k i i nn population n units stratum 1. Stratified sampling method it is important to note that the strata must be nonoverlapping. Samples are then pulled from these strata, and analysis is performed to make inferences about the greater population of interest.
Number of sampling units to be drawn from ith stratum. Random and stratified sampling questions, worksheets, videos. Stratified sampling gcse full lesson teaching resources. This completely negates the concept of stratified sampling as a type of probability sampling. Systematic sampling and stratified sampling are the types of probability sampling design. A random sample may by chance miss all the undeprived areas. Previous rounding highest lowest practice questions. Number of sampling units in ith strata 1 k i i nn ni. Stratified random sampling is a type of probability sampling technique see our article probability sampling if you do not know what probability sampling is. Sampling theory chapter 4 stratified sampling shalabh, iit kanpur page 2 notations. Quota sampling is a nonprobability sampling technique in which researchers look for specific qualities or traits in their respondents, and then take a sample that is in proportion to a population of interest.
Stratified sampling worksheet and exam practice qs teaching. If the groups are of different sizes, the number of items selected from each group. In a stratified sample, a proportionate number of measurements are taken is taken from each group. They can be a little challenging and please do practice all of the problems. Jan 06, 2016 gcse mathematics stratified sampling questions appear on many exam papers and you can download the questions here. The examples are quick and concise with exam style questions, go to gcse maths if you need more indepth explanations. In this method, the elements from each stratum is selected in proportion to the size of the strata. Stratified sampling is a probability sampling method and a form of random sampling in which the population is divided into two or more groups strata according to one or more common attributes.
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