vocabulary ch.1-6

Question 1

statistics

Answer 1

A collection of procedures and principles for gathering data and analyzing infofrmation in order to help people make descisions when faced with uncertianty.

Question 2

Dot plot

Answer 2

represents the response of an individual

Question 3

five-number summary

Answer 3

The lowest value, the cutoff points for 1/4, 1/2, and 3/4 of the data, and the highest value.

Question 4

Mean Average

Answer 4

add all values together then divide by the amount of values.

Question 5

Median Average

Answer 5

if n is odd:
M= middle #
(n+1)/2

if n is even:
M=middle of ordered values
(n/2) and (n/2)+1

Question 6

population data

Answer 6

collected when all inviduals in a population are measured.

Question 7

sample survey

Answer 7

a method for collecting data from or about the members of a population so that inferences about the entire population can be obtained.

Question 8

random sample survey

Answer 8

a sampling method that allows for the randomization of sample selection, i.e., each sample has the same probability as other samples to be selected to serve as a representation of an entire population.

Question 9

categorical variable

Answer 9

consist of group or category names that don’t necessarily have a logical ordering

Question 10

histogram

Answer 10

most commonly used graph to show frequency distributions.

Question 11

extremes

Answer 11

high and low

Question 12

median

Question 13

quartiles

Answer 13

medians of the lower and upper halves of the values.

Question 14

interquartile range

Answer 14

(IQR) upper quartile - lower quartile

Question 15

outlier

Answer 15

data point that is not consistent with the bulk of the data.

Question 16

scatterplot

Answer 16

a two-dimensional graph of data values

Question 17

linear association
- positive
- negative

Question 18

linear regression line
- Y intercept
- slope

Question 19

Correlation r

Answer 19

indicates the strength and direction of a straight-line relationship.
r is always between -1 and 1.

Question 20

statistically significant

Question 21

Null hypothesis

Answer 21

the two variables are not related in the population

Question 22

Alternative Hypothesis

Answer 22

the two variables are related in the population

Question 23

population

Question 24

Bias
- Selection
- non participation or non response

Question 25

margin of error-

Answer 25

calculate with formula: 1/square root n =m.e.

Question 26

Sample size

Answer 26

calculate with formula: (1/m.e.)^2 = n

Question 27

observational study

Answer 27

• researchers observe or question participants about opinions, behaviors, or outcomes.
• researchers don’t assign any treatments or conditions.
• participants not asked to do anything differently.

Question 28

experimental study

Answer 28

researchers manipulate something and measure the effect of the manipulation on some outcome of interest

Question 29

variables

Answer 29

• response
• explanatory
• confounding

Question 30

control group

Answer 30

treated identically in all respects except they don’t recieve treatment. somethings they get dummy treatments like placebos.

Question 31

range

Answer 31

range =high value - low value

Question 32

margin of error

Answer 32

1/ square root (n) x 100%

n= poplulation size

Question 33

population size

Answer 33

n =1/(m.e)^2

Question 34

confounding variables

Answer 34

variable that both affect the response variable and also is related to the explanatory variable.

lurking variable that could be a convounding variable but it’s not measured.