Midterm 1

Question 1

Statistics

Answer 1

science that involves the
-collection of data
- organization
- analyzing
- interpret

Question 2

collection of data examples

Answer 2

• interviews
• questionaiires
• calls
• conducting experiments

Question 3

organization of data examples

Answer 3

• graphs
• bar graph
• histograms
• scatter plots
• dot plot
• stem leaf plot
• lowest to highest
• five number summary

Question 4

analyzing data means

Answer 4

• to make conclusions
• normal distribution
• testing hypothesis

Question 5

discrete data

Answer 5

• finite numbers
• whole numbers

Question 6

continuous data

Answer 6

• infinite
• mixture of whole and decimals

Question 7

qualitative data broken down into:

Answer 7

ordinal and nominal

Question 8

nominal data

Answer 8

• no organization to the order
• religion, race, flavours

Question 9

ordinal data

Answer 9

• order, mathematical sense
• order of grades: A, B, C, D
• ranks (junior officer, senior officer)
• flavours (how good they are)

Question 10

interval data

Answer 10

• quantitative broken down further
• no natural zero, zero has no meaning
• temperature
• years

Question 11

ratio data

Answer 11

• quantitative broke down more
• has natural zero
• bank account
• rental cars
• time of zero for delivery

Question 12

sampling

Answer 12

process of getting samples for analysis

Question 13

statistic

Answer 13

characteristic of a sample

Question 14

parameter

Answer 14

characteristic of a population

Question 15

sampling methods

Answer 15

random
systematic
stratified
cluster
convinence

Question 16

random sampling and advantage

Answer 16

put everything into basket and picking, no bias.
n must be equal or greater than 30.
- without replacement
- advantage- allows equal chances for all samples, not biased

Question 17

systematic

Answer 17

• order, every third for fourth person, pick randomly
• selecting the kth item

Question 18

stratified sampling and advantage

Answer 18

• put the communities into similar characteristics (S, N, E, W)
• those are statas
• then you go to each strat and do random sampling
• n will be properly represented
• youre sure you will get north side representation

Question 19

convinence sampling and disadvantage

Answer 19

pick samples ased on info that is already out there. take your sampling form the good side of town, etc
- biased

Question 20

cluster sampling and disadvantage

Answer 20

similar to stratified
- put into clusters (just like stratas)
- but instead of random sampling, you pick everyone out of the clusters.
- there are so many people, ususally not the best method

Question 21

descriptive stats

Answer 21

• organizing and analyzing

Question 22

inferential stats

Answer 22

• conclusion
• interpreting the data
• testing hypothesis

Question 23

Range

Answer 23

• every set of data has a range
  = H-L

Question 24

outliars

Answer 24

extreme values

Question 25

frequency table

Answer 25

- class and frequency ONLY - all whole numbers

Question 26

how to get class width

Answer 26

= range / # of classes - round to nearest whole # - must include the lowest value

Question 27

frequency

Answer 27

how many times the data comes up on the chart

Question 28

frequency histogram

Answer 28

- class, frequency and boundary

Question 29

boundary

Answer 29

- continuous data (add or minus 0.5 to make it smooth)

Question 30

mode (frequency histogram)

Answer 30

- each of the bars in the bar graph

Question 31

relative frequency table

Answer 31

- percentage of the frequency - frequency divided by the total amount - class, frequency, relative frequency, boundary

Question 32

cummulative relative frequency

Answer 32

- first frequency added to the second, then take that total and add to the third. then you divide by the total to make a percentage - increasing trend - will give you the total - table- class, frequency, relative frequency, cumm, cumm relative frequency

Question 33

mean

Answer 33

ΣXi (n on top, i=1 on bottom)

Question 34

median

Answer 34

M - middle value - (n+1)/2 th position

Question 35

mode

Answer 35

most occuring, highest frequency

Question 36

Mid range

Answer 36

H plus L / 2

Question 37

5 number summary

Answer 37

L, Q1, M, Q3, H

Question 38

Q1, Q3

Answer 38

from the median- (n+1)/2 th position

Question 39

Box plot

Answer 39

five number summary - can have multiple boxes on the plot just number on the x axis - horizontal or vertical

Question 40

Q2

Answer 40

Q3-Q1

Question 41

Standard deviation

Answer 41

(s) - measure of how far your point is from the mean - measures variation = (square root) Σ[(x-xbar)]2 / n-1

Question 42

variants

Answer 42

s2 - standard deviation squared

Question 43

skewness

Answer 43

M, mode, mean - normal, positive, negative

Question 44

stem leaf plot

Answer 44

- no commas - start filling leafs from the stem - leaf can hold only one element, the last - give # room

Question 45

event P(A)

Answer 45

action of interest - the A variable

Question 46

represent a probability how

Answer 46

percentage, decimal, fraction - all probabilities should add up to 1

Question 47

independent events

Answer 47

the occurance of A does not depend on the occurance of B

Question 48

mutually exclusive event (disjoint)

Answer 48

events cannot happen at the same time

Question 49

mutually inclusive events (adjoint events)

Answer 49

can happen at the same time

Question 50

simple events

Answer 50

one experiment happens at a time and will have a single outcome (tossing a coin)

Question 51

compound events

Answer 51

- the event has more than one outcome (rolling a dice)

Question 52

contingency table

Answer 52

compares two quantitative variables - totals on both sides - title

Question 53

P(AUB)

Answer 53

- union - covering all percentages of A and B

Question 54

P(A∩B)

Answer 54

- intersection

Question 55

conditional probability P(A/B)

Answer 55

- given that =P(A∩B)/P(B) - events must be inclusive, have an intersection - something in common

Question 56

Discrete Probability characteristics

Answer 56

1) all the x values are whole #'s (discrete) 2) probabilities are positive and lie between 0 and 1 3) summation of probabilities is 1

Question 57

mean of a discrete probability

Answer 57

µx= ΣxiPi = xiPi + x2P2 .... xnPn

Question 58

variance of discrete probaility

Answer 58

σ2x = Σ(xi-µx)2 Pi

Question 59

standard deviation

Answer 59

square the variance