data management ch 1

Question 1

population

Answer 1

the entire group of the study

Question 2

sample

Answer 2

a selection of some individuals from the population

Question 3

cross-sectional data

Answer 3

observational study made a specific point in time

Question 4

longitude

Answer 4

measured the variables over a long period of time

Question 5

raw-data

Answer 5

unprocessed information collected for a study

Question 6

qualitative variable

Answer 6

cannot be measured numerically

Question 7

quantitative variable

Answer 7

can be measured nymerically

Question 8

discrete data

only quantitive

Answer 8

measured with whole numbers

Question 9

continuous data

only quantitive

Answer 9

measured with a given range

Question 10

ordinal variable

Answer 10

can be put into relative order

Question 11

nominal variable

Answer 11

categories that cannot be ordered

Question 12

what are the titles for the circle graph chart

the chart for the information for the graph

Answer 12

1. title
2. percent of what people like
3. angle

Question 13

how to find the angle for a circle graph

Answer 13

the percent people like * 360

Question 14

how does a stem and leaf plot key work

give an example

Answer 14

you can use any random number and show how it would look in the stem and leaf plot

1|3 means 13

Question 15

how does a pictograph key work

Answer 15

each (picture) represents % of (title)

Question 16

what is a frequency table

Answer 16

how many things there are

Question 17

what are the titles for the frequency table chart

Answer 17

1. # of __ / interval
2. tally
3. frequency
4. midpoint (if you’re using intervals)
5. cumulative frequency (if question asks)
6. relative frequency (if question asks)

Question 18

how to calculate cumulative frequency

Answer 18

adding up the frequency one row at a time

Question 19

how to calculate relative frequency

Answer 19

frequency / total freq

Question 20

what is the point of a bargraph and what is it used for

Answer 20

for categorial or discrete
no touching indicates separation between groups

Question 21

what is a frequency polygon

Answer 21

same information as a bar graph but simpler to look at

Question 22

what is a cumulative frequency graph (ogive)

Answer 22

the running total from lowest to highest

Question 23

what is a histogram

Answer 23

a bar graph but the bars are touching
!! the x values are not intervals, the bars are in between the values!!

Question 24

how to use the brackets for intervals

Answer 24

”[” means exact ≤
“(“ means anything but <

Question 25

relative frequency polygons y values

Answer 25

go up from (0-1) | 0.1, 0.2, 0.3

Question 26

median

Answer 26

middle value

Question 27

mean

Answer 27

added total frequency / numbers of frequency

Question 28

mode

Answer 28

the most occuring number

Question 29

simple mean equation | with sigma

Answer 29

x̄ = Σx / n x̄ = sample mean n = total # value in sample Σ = "the sum of"

Question 30

weighted mean sample equation

Answer 30

X̄w = Σxw / Σx ## Footnote the denomenator will always equal 100%

Question 31

what is the interquartile range (IQR)

Answer 31

range of the middle half data

Question 32

how to find the IQR

Answer 32

Q3 - Q1 = IQR

Question 33

how to find the upper threshold | for modified box and whisker plot

Answer 33

1. IQR * 1.5 2. Q3 + IQR

Question 34

how to find the lowerthreshold | for modified box and whisker plot

Answer 34

1. IQR * 1.5 2. Q1 - IQR

Question 35

how to find the semi-interquartile range (SIQR)

Answer 35

IQR + (IQR/2)

Question 36

population deviation formula

Answer 36

x - μ μ = population x = point of data

Question 37

sample deviation formula

Answer 37

x - x̄ x = point of data x̄ = sample

Question 38

population variance formula

Answer 38

σ^2 = Σ(x-μ)^2 / N σ = population Σ = "the sum of" μ = population mean N = # of elements in population

Question 39

population standard deviation formula

Answer 39

σ = √[Σ(x-μ)^2 / N] σ = population Σ = "the sum of" μ = population mean N = # of elements in population

Question 40

sample variance formula

Answer 40

S^2 = Σ(x-x̄)^2 / n - 1 S = sample Σ = "the sum of" x̄ = sample mean n = # of elements in population

Question 41

sample standard deviation formula

Answer 41

S^2 = √[Σ(x-x̄)^2 / n - 1] S = sample Σ = "the sum of" x̄ = sample mean n = # of elements in population

Question 42

popular standard deviation for grouped data formula

Answer 42

σ = √[Σf * (x-x̄)^2 / N]

Question 43

when finding the standard deviation we use a table to stay organized. what are the titles for the table

Answer 43

1. x 2. x - x̄ 3. (x - x̄) ^2 | change x̄ to μ for population insted of sample if appicable

Question 44

when finding the weighted standard deviation we use a table to stay organized. what are the titles for the table | there are 6 titles

Answer 44

1. x 2. frequency (f) 3. culminating frequency 4. x - x̄ 5. (x - x̄)^2 6. f * (x - x̄)^2 | change x̄ to μ for population insted of sample if appicable

Question 45

how to get the deviation graph threshold

Answer 45

(mean ± standard deviation) μ - σ = threshold -1 μ = threshold 0 μ + σ = threshold 1 μ + σ = threshold 2

Question 46

sample z-score formula

Answer 46

x-x̄ / s deviation / standard deviation)

Question 47

population z-score formula

Answer 47

x-μ / σ (deviation / standard deviation)

Question 48

what is an index

Answer 48

the value of a variable (or group of variables) to a value of a particular date

Question 49

how to find the slope

Answer 49

m = y2-y1 / x2-x1

Question 50

factor grow/ fall formula | in a stock graph for example

Answer 50

(new number / old number) * 100 = percent grown/ fall

Question 51

percent change formula

Answer 51

1. find the percent change 2. subtract 100 from the answer in 1

Question 52

how to find how much money your stock will go up depending how much you put | formula

Answer 52

multiply it with the rate of change (money invested) * y2-y1/x2-x1 = $$

Question 53

random sampling

Answer 53

literally anything that is 100% random * random number generator * pick out of a hat

Question 54

systematic random sampling | what is it, what formula do you have to use and why

Answer 54

* every nth person * have to pick a random starting point n = (population size) / (sampeling size) * n is the number of people you jump

Question 55

stratified random sampling

Answer 55

* population is divided into subgroups based on qualities 1. 'relative frequency' is -> # of students / total # of students 2. '# of surveyed in sample' is RF * (survey size %) survey size % = % of total amount of students

Question 56

cluster random sampling

Answer 56

* divide population into groups * randomly select a few of the many groups * survey everyone in the group unreliable if clusters are not representing the whole population

Question 57

multistage random sampling

Answer 57

* multiple levels of random sampling bias from some areas around the world are not diverse 1. randomly choose city 2. randomly choose block 3. randomly choose houses within the block

Question 58

convenience sampling - non random

Answer 58

* asking people something - bias from unrepresented data -> only ask friends

Question 59

voluntary sampling - non random

Answer 59

* people who willingly take the survey - bias from super strong opinions of hate/ love - people who dont care dont care

Question 60

what is a bias

Answer 60

occurs when a sample is not representative of the population

Question 61

sampling bias

Answer 61

dose not accurately represent the population * football game, asked for football or band equipment

Question 62

household bias

Answer 62

different groups are not polled proportionally to their size * 10 students sampled from each grade but there are more gr 9 students

Question 63

measurement bias

Answer 63

the way data was collected influences the results also happens when something is unnatural or unclear * sign says slow down but you're trying to find how many people speed

Question 64

leading question bias

Answer 64

pushes people to answer in a certain way * what are your fav songs, give 3 options

Question 65

loaded question bias

Answer 65

certain words that imply a certain response * do you really intend...

Question 66

non-response bias

Answer 66

people choose not to participate also non participation of certain groups * group of students respond to a survey about school activities

Question 67

response bias

Answer 67

feel embarrassed to give honest answers also poorly written questions *do you do illegal things (not anonymous)