10.6 Representing Variation graphically

Question 1

Discontinuous Variation

Answer 1

A characteristic that can only result in certain values.

Variation purely determined by genetic factors. Controlled by a single gene.

An animals sex, shape of bacteria

Pie or bar chart

Question 2

Continuous Variation

Answer 2

A characteristic that can take any value within a range

Controlled by a number of genes and are often influenced by environmental factors

Frequency table, histogram, curve.

Question 3

Normal Distribution Curves

Answer 3

The mean mode and median are the same

Characteristic bell shape which is symmetrical about the mean

50% are less than the mean and 50% are more than the mean

Most values lie close to the mean value

Question 4

Standard Deviation

Answer 4

A measure of how spread out the data is.

High SD means high variation

Question 5

Students T Test

Answer 5

used to compare the means of data values of two populations

Data must be normally distributed and enough data collected to find a reliable mean

accept of reject null hypothesis based on whether your value is higher of lower than that in the table at the 0.05 level. If you can be more than 95% sure the data is significant, reject the null hypotheisis, if not accept it.

Question 6

Spearman’s Rank correlation coefficient

Answer 6

no correlation- no relationship between the data

positive correlation-as one set of data increases in value, so does the other

Negative correlation- as one set of data increases in value, the other decreases in value.

To be significant, you must have a certainty of 95% or greater