Data, Graphs and Statistics Flashcards
Probabilistic notation form?
P(event)
What does 0 mean in probability?
Impossible event
What does 1 mean in probably?
Certain event
What is theoretical probability?
Does not take take experimental data or bias into account
Formula for theoretical probability?
Number of ways even can occur
P(Y)= ————————————————
Total number of sample points
What is experimental probability?
Determined by performing an experiment and using data
Formula for experiment probability?
Number of ways event does occur
P(Z) = ———————————————-
Number of times experiment repeated
What is an independent event?
The results of one event does not affect the result of another
How to calculate the probability of multiple independent events?
Multiply together probabilities
May need to sum together and multiply more if we do not care about the order
How to use a tree diagram?
Multiply along the branches
Add up probabilities at end if needed
What is a depend event?
The outcome of the first event affects the second event
What is the expectation is probability?
The value we expect to happen
How to work out expectation?
Multiple each outcome by its probability
Add all these together
What is the expected frequency?
Used when expectation is not possible. E.g. cannot multiple green by 7
How to work out expected frequency?
Multiply the probability of the outcome by the amount of times we did the experiment
What is continues data?
Data can take any value, any number of decimals
Why is discrete data?
Only can be from a specific set of numbers, usually a whole number
What is categoric data?
Non-numerical categories. Can’t usually be ordered
What graph is used for categoric data?
Bar chart (horizontal bars) Pie chart
How to change percentage to degrees for a pie chart?
Multiply by 3.6
What type graph is used for discrete data?
Bar chart (vertical bars) Pie chart Histogram (useful for date with ranges) they represent frequency by the area of the bar rather than height
What type of graph is used for continuous data?
Line graphs Scatter graphs (when both axis are continuous)
What do scatter graphs show?
Used to show whether there is a relationship between two sets of data
What is a negative correlation?
As one quantity increases the other decreases
What is a positive correlation?
As one quantity increases so does the other
What does no correlation mean?
No clear relationship between quantities
What type of graph has a best fit line?
Line graph NOT scatter graph
Reliability definition in regards to line graphs?
If all the points are close to the line of best fit with no anomalies
What does proportional mean in regards to line graphs?
Only if the line of best fit passes through the origin
What is the name of the equation that the graph represents?
The function
What is the domain?
The spread of the x values
What is the range?
The spread of y values
On a domain/range line what does a hallow or full circle mean?
Hallow means greater than or less than
Full means greater than, less than or equal to
How should decimals and significant figures be used in a table?
Going down a column where data is being measured there should always be the same number of decimal places
If data is being added or subtracted decimal places should also be maintained
If data is multiplied or divided then significant figures should be maintained rather than decimals
What is central tendency?
As we get more observations we tent towards a central value rather than an extreme value
How to calculate arithmetic mean?
Sum of all the values and divided by the number of values
Advantages of arithmetic mean?
Most efficient measure of central tendency
Disadvantages of arithmetic mean?
Can be substantially affected by large outliers
How to work out the mode?
The most common value