BAI211 Exam 2

Bubbleplot

Shows the relationship between three numerical variables.

null hypothesis

denoted as H0. a presumed default state of nature or status quo.

Type II error

is made when we do not reject the null hypothesis when the null hypothesis is actually false.

mean of a large sample

n<30

mean of a small sample

n>=30

confidence interval

population mean, population proportion,

Relative frequency distribution

shows the proportion of the total number of observations associated with each value or class of values and is related to a probability distribution, which is extensively used in statistics.

Type I error

committed when we reject the null hypothesis when the null hypothesis is actually true

frequency distribution

A tabular method for condensing and summarizing data

test statistic

= (observed value) - (expected value)/standard error

Scatterplot

A graphical tool that helps in determining whether or not two numerical variables are related in some systematic way. Each point represents a paired observation for two variables.

Histogram

A series of rectangles where the width and height of each rectangle represent the interval width and frequency of the respective interval

Alternative hypothesis

Denoted as HA. contradicts the default state or status quo.

Line Chart

Displays a numerical variable as a series of data points on a line. Useful for tracking changes over time.

mu = E(x)

Expected value in the population of x

Central Limit Theorem (CLT)

The sum or the average of a large number of independent observations from the same underlying distribution has an approximate normal distribution.

sample distribution

a frequency distribution of a sample. Sample mean, sample proportion.

contingency table

a tabular representation of categorical data . A contingency table usually shows frequencies for particular combinations of values of two discrete random variable s X and Y. Each cell in the table represents a mutually exclusive combination of X-Y values.

Heat Map

an important visualization tool that uses color or color intensity to display relations between variables.