AS Maths Statistics - Edexel

Name the conditions neede to carry out binomial distribution

Fixed number of trials

FIxed probability of success

Independent trials

Two possible outcomes

what is a census

something htat measures every number of something in a population

what are the pros of doing a cencus

provides an accurate result of the population

what are some cons of doing a cencus

they are expensive and time consuming

what is a sampling unit

they are individuals in a population

what is a sampling frame

list of all individuals in the population

describe how to conduct random sampling

• number all individiuals in a population with a unique number

• using a random number generator generate the number of numbers you need based on the sample size

• disregard any repeated numbers and generate a new number untill all numbers in the sample are unique

• carry out investigation on the samples

what are the pros of random sampling

bias free

what are the cons of random sampling

need a sampling frame

how do you conduct systematic sampling

assign each member a unique nukberr, select a number and repeat very nth unit

pros of systematic sampling

quick to use

cons of systematic sampling

need of sampling frame

what is stratified sampling

sample represents strata, population is divided into strata and then pick random number of memebers in each group

hwat are the pros of stratifified sampling

reflects whole population, so is less bias

what are the cons of stratified sampling

population must be classified into strata

what is quota sampling

strata filled out by interveiwers/ researchers

what are the pros of quota sampling

there is no need for a samplign frame

what are cons of stratified sampling

not random so there is bias

what is oppurtunity sampling

quota filled by availble population, eg standing outside a supermarket and intervewing the first 20 people you see

what are the pros of oppurtunity sampling

easy and cheap

what are cons with oppurtunity sampling

unlikely to respresnt the whole population

what are the places in the large data set

UK: Leuchars, Leeming, Heathrow, Horn, Camborne

International: Jacksonville, Perth, Beijing

why isn’t the data for some values measured e.g. rainfall accurate

because there is missing data and errors

What does it mean to clean data

remove anomalous results and missing data from averages

what is the null hypothesis

the hypothesis we assume to be true

what is the alternative hypotheis

the hypotheiss which is true if the null hypothesis is false

what is the significance level

the given threshhold of likliness

what is as one tailed test

when h1>k or h1<k

when is it a two tailed test

when h is not equal to k

what is the test statistic

the number of successes observed

when do you reject the null hypothesis

when probability is less than the significance level

when do you accept the null hypothesis

when the probability is greater than the significance level

Quantitative data

Associated with numerical data

Qualitative data

non-numerical data

Continuous

data can be any value in a given range

Discrete

data can only be specific values in a given range