Exam II Lecture 10 Stats 1

Question 1

Difference between population and sample.

Answer 1

Population includes all of the individuals being studied.’

Samples are a subcollection of members selected from the population.

Question 2

Dependent variable vs independent variable

Answer 2

Influenced by another factor, it is what you are trying to measure.

The independent variable influences the dependent factor

Question 3

Parameter vs statistic

Answer 3

PAramaters are mathematical descriptions of a population characteristic.

Statistics are a mathematical description of a sample characteristic.

Question 4

Descriptive statistics

Answer 4

Summarize and describe the characteristics of data numerically and graphically

Question 5

categorical data

Answer 5

names, labels etc.

Categorical data.

Question 6

Quantitiative data

Answer 6

consists of numbers representing measurements.

Further broken into discrete and continuous measurements.

Question 7

Discrete data

Answer 7

A type of quantataive data where the numbers are finit/countable.

Ex: Number of eggs a hen lays or people admitted to ER.

Question 8

Continuous data

Answer 8

A type of quantatative data in which the result is infinitely possible.

Question 9

Nominal measurement

Answer 9

data consiting of names, labels, or categories.

LEAST PRECISE LEVEL OF MEASUREMENT.

Question 10

Ordinal level of measurement

Answer 10

Data that can be put into some sort of order. but the dfferences between data values is not meaningful.

example race placement.

Question 11

Interval level of measurement

Answer 11

Much like ordinal level in that they can be paced in order but there is no COMMON STARTING POINT OR ZERO POINT.

Example is temeprature scale or sea level.

Question 12

The most precise scale of measurement

Answer 12

Ratio level
Interval level with additional property that there is also a natural zero starting point.

Examples: Height, weight, price of college text books.

Question 13

Observational study

Answer 13

Observing and measuring specific characteristics without attempting to modify the subjects being studied.

NO MANIPULATION OF SUBJECTS.

Question 14

Experimental study

Answer 14

Apply some treatment and then observe its effects on the subjects.

Question 15

Relative frequency distribution

Answer 15

Class frequency / Sum of all frequencies.

to make it a percentage frequency, just multiply by 100%

Question 16

Ogive graph

Answer 16

A line graph that depicts cumaltive frequncies.

Question 17

Bar graph

Answer 17

Uses bar to depict QUALITATIVE VARIABLES

Vertical scale is values horizontal scale is the different categories of qualitative variables.

Question 18

Linear correlation coeficient

Answer 18

Known as r
Or PEarson correlation coeficient

Measures the strength of the linear relationship between the paired quantitative X and Y values within the sample.

If R=0 there is no correlation.

Question 19

Describe the itnerpretation of R (linear correlation coeficient)

Answer 19

the absolute value of r indicates strength of the relationship.

r is not affected by choice of x and y.

r is very sensitive to outliers.

Question 20

Describe the strength of r the linear correlation coeficient.

Answer 20

.8-1 very strong.
.6 - 8 strong
.4 to .6 moderate
.2 to .4 weak
.0 to .2 wear or no relationship.