10.5 - quantitative investigations of variation Flashcards
1
Q
describe the process of random sampling.
A
- divide area into grid with numbers
- use random number generator to select square
2
Q
what ways could be used to minimise chance?
A
- increase sample size (eg. more quadrats / individuals selected)
- analyse with statistical tests
3
Q
what is a sampling bias?
A
selection process is biased deliberately/unwittingly
4
Q
what is a bell-shaped normal distribution curve & how is its shape?
A
symmetrical around central value, mean = mode = median
5
Q
what is a negative skewness?
A
shifts to the right, mode > median > mean
6
Q
what is a positive skewness?
A
shifts to the left, mode < median < mean
