Stats Chapter 2 Lecture 1

Descriptive statistics and Inferential statistics

two branches of statistics:

Descriptive statistics

organize and summarize data we actually collected

Inferential statistics

use the sample to draw conclusions about a larger population

Descriptive statistics

what branch of statistics includes: charts, graphs, tables and numerical summaries (mean, median, standard deviation, IQR)

Inferential statistics

what branch of statistics includes: hypothesis tests and confidence intervals

variable

a characteristic that can be assigned a number or category

Observational unit

the individual or thing we collect data on

UPPERCASE: Y

notation for variables is ______

lowercase: y

notation for observed values is _______

Categorical and Numerical

two main types of variables:

Qualitative

Quantitative

Categorical = _____

Numerical = _____

categorical

word data is what type of variable

numerical

measured data (any value in a range) is what type of variable

numerical

Height, weight, blood pressure, temperature are all examples of _____ variables

categorical

blood type, sex, species, diagnosis, yes/no are all examples of _____ variables

categorical

A nurse records whether each patient is 'independent,' 'needs assistance,' or 'fully dependent' for daily activities. What type of variable is this?

sample

We almost never study an entire population - we study a ______.

parameters

We use those statistics to estimate the true population values called ______

statistics

parameter

from the sample = _______

of the population = _______

statistic

Calculated from data we actually collected

parameter

The true value for the entire population

KNOWN

in statistics, the value is _____

UNKNOWN (we estimate it)

in parameter, the value is usually ______

ȳ, s, p̂

Statistic notation: ______

μ (mu), σ (sigma), p

Parameter notation: _______

ȳ

statistic notation for sample mean is _____

s

statistic notation for sample standard deviation is _____

p̂

statistic notation for sample proportion is ______

μ (mu)

parameter notation for population mean is ______

σ (sigma)

parameter notation for population SD is ______

p

parameter notation for population proportion is ______

samples

populations

Descriptive stats describe _______

Inferential stats generalize to ______

one row

Observational unit = typically ______ of data