Quantitative investigations of variation

Question 1

what are two requirements for sampling?

Answer 1

• large sample size so that the sample is representative of the population
• random sampling so that it avoids bias

Question 2

what is the mean?

Answer 2

add up all measurements and divide by the total number. on normal distribution curves the mean measurement is the same as the mode and median

Question 3

what is the mode?

Answer 3

the most common value

Question 4

what is the median?

Answer 4

middle value when lined up in numerical order

Question 5

what is standard deviation?

Answer 5

the measure of the spread of data from the mean

Question 6

what is the range?

Answer 6

the largest minus the smallest value

Question 7

if standard deviations overlap, what does this tell us about the data?

Answer 7

there is likely to be no significant difference between the means of the two sets of data

Question 8

if standard deviations do not overlap, what does this tell us about the data?

Answer 8

there is likely to be a significant difference between the means of the two sets of data