Statistics (1) Flashcards
What is a population?
Entire group of individuals
What is a sample?
Represents populations which are too large
What is a variable?
Condition which can take on a different value
Name 2 types of data
Categorical and Numerical
Describe 2 types of categorical data
- Nominal (no order to values)
- Ordinal (some sort of order)
Describe 2 types of numerical data
- Discrete (fixed numbers)
- Continuous (infinitely divisible)
Name 3 measurements of central tendency
- Mean
- Mode
- Median
Name 3 measurements of dispersion
- Range
- IQ range
- SD
What is the mean?
Average
What is the mode?
Most frequently occurring value
What is the median?
50th percentile value
What is range?
Highest to lowest point
What is interquartile range?
25th to 75th percentile giving middle 50% of values
What is standard deviation?
How close values are scattered around mean
What is standard error of the mean?
SD of number of means from different samples of same population
Name and describe 4 scales used in statistics (in order from weakest to strongest)
- Nominal Scale
Unordered categories set by name (only same or different) - Ordinal Scale
Ordered categories set by name (shows direction of change) - Interval Scale
Equal difference with arbitrary 0 point (e.g temp in C) - Ratio Scale
Interval scale with 0 meaning none of variable present (e.g temp in K)
What is the function of confidence intervals?
Way to indicate probability of mean for the population lies within range of values in sample
