univariate statistical analysis

Question 1

frequency distribution

Answer 1

a set of data organised by summarising the number of times a particular value of a variable occurs

Question 2

the normal distribution

Answer 2

a symmetrical, bell shaped distribution that describes the expected probability distribution of many chance occurrences

Question 3

standardised normal distribution

Answer 3

• the mean identifies the normal curves highest point
• the standardised normal distribution has a mean of 0 and a standard deviation of 1

Question 4

sample distribution

Answer 4

a frequency distribution of a sample

Question 5

sampling distribution

Answer 5

a theoretical probability of sample means for all possible names of a certain size drawn from a particular population

Question 6

central limit theorem

Answer 6

• theory = as the sample size increases, the distribution of sample means becomes approximately normal — regardless of the shape of the population distribution.

Question 7

point estimates

Answer 7

an estimate of the population mean in the form of a single value, usually the sample mean

Question 8

confidence intervals

Answer 8

• a specified range of numbers within the population is expected to lie
• a percentage that shows how confident a researcher can be about being correct

Question 9

three main influences of determining sample size

Answer 9

• Confidence interval
• Sample variability
• level of acceptable error