Statistics Flashcards
What is statistics?
The study of collecting, presenting, analysing and interpreting data.
What is a measure of the amount of how close the entire set of data is to the average value?
Standard deviation
If a population of the data has a normal distribution how much of the data are included in a range of 1 standard deviation above and below the mean?
68.20%
What type of distribution is shown in a a graph with the peak skewed to the left?
In the middle?
Skewed to the right?
Positively skewed distribution
Symmetrical distribution
Negatively skewed distribution
What is true regarding negatively skewed distribution?
The mean is usually LESS than the mode
What’s an example of a continuous variable?
The distance from Guildford to london
Discrete data is from quantities that can be…
Counted
If data shows a positive skew, the mean median and mode are normally in the order of:
Mode, median and then mean
The Standard Error of the Mean (SEM) gives an indication of…
How close a sample mean might be to the population mean.
If you have 2 sets of variables (X and Y) and want to use KNOWN values of X to predict UNKOWN values of Y you are best to use a…
Regression Test
My R squared regression value is 0.9, this means that my data points are…
More TIGHTLY spread around a line of best fit than another set with R squared = 0.2
What is the correct description of regression analysis?
Regression analysis is used to quantify how 1 set of data relates to another set
It is used when 1 of the variables is dependant on the other (independent) variable
Linear regression is used where a linear (straight line) r’ship is between the variables.
What is the difference between parametric and non- parametric data?
Parametric follows a distribution / non- parametric does NOT
What is the WRONG description about Inferential Statistics?
Inferential statistics are those that describe data in a sample (they are statistical methods!)
In Statistical Hypothesis testing, what is correct?
The Null Hypothesis is generally the opposite of what we’re interested in finding out
If there’s a statistically significant difference (P<0.05) then the null hypothesis is REJECTED
If we’re interested in whether there’s a difference between the 2 groups, then the null hypothesis is that there’s NO difference.
