Daily Agenda - Kenston Local Schoolskenstonlocal.org/baugher/wp-content/uploads/2015/06/Chapter-4... · Daily Agenda 3. Notes 4.2 Quiz ... Seed Calculator with number 555 (just for

Chapter 4 Section 1 day 3 2016s Notes.notebook

1

March 18, 2016

Aug 23-8:26 PM

Honors Statistics

Aug 23-8:31 PM

Daily Agenda

3. Notes 4.2 Quiz

4. Check homework C4#3


2

March 18, 2016

Mar 12-12:06 PM

Apr 6-9:53 AM

line 107


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March 18, 2016

Oct 27-7:07 PM

Use two digit numbers from 01 to 40

Start at line 107 choose two digit numbers.

Continue until 5 two digit numbers from 01 to 40 are selected

82 73 95 78 90 81 67 65 53 00 94

Sample consists of the following classmates.

Johnson (20)

Rider (31) Calloway (07)

Oct 27-7:09 PM

Use two digit numbers from 01 to 33

Start at line 117 choose two digit numbers.

Continue until 3 two digit numbers from 01 to 33 are selected

Sample consists of the following complexes

Fairington (16) Fowler (18)

79 85


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March 18, 2016

Oct 31-12:11 PM

Oct 27-7:09 PM

Use numbers from 1 to 1410

RANDOM: Use calculator command to generate random numbers

RANDINT(1,1410,1)

Stopping Procedure: Continue until 141 DIFFERENT numbers from 1 to 1410 are selected

Sample consists of the following plots. (do only first 3)

Seed Calculator with number 222 (just for classroom purposes)


5

March 18, 2016

Oct 27-7:09 PM

Use numbers from 1 to 55,914

RANDOM: Use calculator command to generate random numbers

RANDINT(1,55914,1)

Stopping Procedure: Continue until 395 DIFFERENT numbers from 1 to 55914 are selected

Sample consists of the following gravestones.(do only first 3)

gravestones 43962, 1387, 4182

Seed Calculator with number 555 (just for classroom purposes)

Oct 27-7:10 PM

the theoretical probability of four 0 in 40 digits is

exactly 4 but this will not always occur with a "random" sample

of 40 digits.

with 10 digits possible there is a 1/100

chance of two digits being 00 (or 100)

, this will not happen very often but there is a chance that

four digits could be the number 0000. One out of 10,000 chance that

it will occur. ALSO, this number 0000 is just as likely as any other 4

digits!! Think about it.


6

March 18, 2016

Oct 27-7:10 PM

Picking the same "Random" sample each time will not

result in your samples being "Random" any longer....

Oct 27-7:10 PM

To find the sample of 20 randomly selected phones might be a

problem if you waited until the end of the day. Perhaps the managers

could select 20 numbers from 1 to 1000 ahead of time. But then you

would not want to tell the people manufacturing the phones which ones

were selected for inspection ...

b) The last 20 phones are not a random sample so Bias could result.

Perhaps the last 20 phones are of poorer quality than the first phones

manufactured. Tired people or tired machines (over heated, etc.) could

result in the ending phones not having the same quality.

This is NOT a Simple Random Sample because all possible groups

of 20 phones would not be equally likely to be selected. It would be

impossible (probability = 0) for the 20 phones in a row to be selected.

Perhaps 20 phones in a row might be a desirable group occasionally.


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March 18, 2016

Oct 27-7:10 PM

It would take a very long time (and time is money) to count and label all of the trees in the Rocky Mountain National Park.

An SRS is not a pratical way to sample in this setting.

sample could result in a bias sample. Perhaps the car

emissions are contributing to the trees dying and would

produce a result that overestimates the dead trees.

c) Scientists should not conclude that exactly 35% of all pine trees on the

west side of the park are infested because the sample yielded 35%. If the

sampling method was carried out correctly they should have confidence

that the approximate tree infestation is 35%. Sampling variability is the

concept that each time a sample is selected it could result in different

estimates of the true population "answer". These estimates should only

slightly vary with proper sampling techniques.

Oct 27-11:38 AM


8

March 18, 2016

Oct 27-11:26 AM

Apr 5-5:14 PM

4.23 Is it a SRS?

Population: 2000 male engineers 500 female engineers 200 male engineers 50 female engineers

Is this sample a SRS?

Simple Random Sample

simple random sample (SRS) of size consists of individuals from the population chosen in such a way that every set of individuals has an equal chance to be in the sample actually selected.

While all people have the same probability

of being selected (1 out of 10) not all

sample groups are possible because of the

pre-grouping. (which is good for this but not SRS)

There cannot be all females (a group of

250 females) or all males (250 males) sent

to the "activity" training, meeting, etc.


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March 18, 2016

Oct 26-4:54 PM

Nov 5-12:24 PM


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March 18, 2016

Apr 5-5:13 PM

methods of sampling

probability samplingsimple random sampling (SRS)stratified random samplingcluster samplingsystematic random samplingmultistage sampling

voluntary responseconvenience sample

involves studying a part in order to gain information about the whole.

Sampling Frame

A sampling frame is the LIST of individuals from which a sample is selected. This list should include all of the intended population of interest.

Oct 27-3:08 PM

Picking a Sample ... Names out of a hat

Label

Random

Rules

Identify


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March 18, 2016

Oct 31-12:11 PM

Oct 28-7:59 PM

Stratified random sampling works best when the individuals within each stratum are similar with respect to what is being measured and when there are large differences between strata.


12

March 18, 2016

Oct 28-8:05 PM

Oct 28-9:35 PM


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March 18, 2016

Nov 7-10:14 AM

Simple Random Sampling:

1. Obtain a list of all KHS students and their unique student ID #s,2. Use computer software (or the random digit table) to generate

students' ID #s that will be included in our sample.(Every student every group has an equally likely chance of being chosen for the sample.)

Stratified Random Sampling:

1. Divide students into meaningful groups, for example, by grade level.2. Obtain a list of all KHS students and their unique student ID #s,

divided up by grade level,3. Use computer software (or the random digit table) to generate students'

ID #s within each grade level that will be included in our sample.(Every student does not have an equally likely chance of being chosen out of the population to be in the sample. Every student in a sub-group has an equally likely chance of being chosen from that sub-group to be in the sample.)

Cluster Sampling:

1. Divide students into meaningful groups, for example, by homerooms.2. Obtain a list of all homerooms and assign unique numbers to each one,3. Use computer software (or the random digit table) to generate

homeroom numbers that will be included in our sample.(Every student does not have an equally likely chance of being chosen out of the

chosen out of all the homerooms to be in the sample.)

Oct 28-9:34 PM

CLUSTER SAMPLING because they randomly

selected the blocks and then contacted all the families in the

selected block.

b) The company most likely chose this method because it would

less time to gather the information from "blocks" of families

rather than travel all over the subdivision to seek out the

randomly selected families for the survey.


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March 18, 2016

Apr 5-5:18 PM

100% of largest accounts are verified500 in amounts $1000 to $50,000 4400 in amounts under $1000

LABEL:

TABLE:

STOPPING PROCEDURE:

IDENTIFY SAMPLE:

(let's only do the first 3 for practice)

Oct 30-11:24 AM

This would take much time and effort, you may also get a sample that mostly includes the "cheap" seats and

therefore your sample would under-estimate the population proportion of financial status.

Using lettered rows would be the best choice. You could then

randomly select from expensive to cheap seats.

For clusters choose the numbered sections. Each section

contains all the different prices of seats so you would

have a sample that represents the population.


15

March 18, 2016

Oct 29-12:43 PM

Convenience Sampling often produces unrepresentative data.

Bias is NOT just bad luck in one sample.

It's the result of a bad study design!

People who choose to participate in call-in, text-in, or phone-

in surveys are usually NOT representative of some larger

population of interest. They have strong feelings about the

Oct 29-3:46 PM

Be sure you understand the difference between

CLUSTER - a group of individuals that are a smaller image of the population.

Cluster - diverse like the population.

Some students misuse the term "Voluntary Response" to

explain why some randomly selected people do not respond

in a sample survey. (This is called NON- RESPONSE)


16

March 18, 2016

Oct 31-11:45 AM

VISCOG

http://www.theinvisiblegorilla.com/gorilla_experiment.html

Apr 6-9:53 AM

line 107


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March 18, 2016

Oct 28-8:12 PM

I would recommend to make strata based on the ticket type.

I recommend this because the tickets are different prices and

the athletic department would be able to receive opinions from the

people in the three different price ranges of seats. They would

most likely be purchasing different concessions (or different

amounts of concessions). Perhaps I would also add an additional strata of home sideline, visitor sideline, home corner, visitor

corner, home endzone, and visitor endzone. This way I would

include visiting opinions if the survey would benefit from that type

of information.

I would recommend the same grouping for the clusters. Home and

visitor sideline, corner, and endzone seating.

Using a stratified random sample will involve selecting random people from

the strata that are all over the stadium. This would be very difficult to keep

track of and very time consuming.

A cluster sample would be easier to obtain because you could randomly

pick a seat section from the "sideline" cluster. (Home sideline 26, 25, 24,

23, 22, 21, 20) and use all people in this section to answer the survey

question. This could be done by placing a survey on their seats before the

game starts and then having a person collect the survey from the people in

the section.

Oct 28-9:33 PM

(30)(40) = 1200 rooms

The Hotel manager will want to obtain information from people who stay

does not guarantee that a variety of guests will be selected (you could get

every one from the bottom floor golf course side ...)

The Strata should be grouped by view side and floor level. Level 1 golf,

Level 1 water, Level 2 golf, Level 2 water, .... Level 30 golf, Level 30

Then choose 2 guests (or rooms) from each strata (there are 60 strata, 2

views per 30 floors).

b) The floors could be used as clusters. This would make collection of the data easier (only survey 3 floors) but ...

from my experience, my stay is effected by those guests in rooms directly around, above and below me, so clustering could add an unintended BIAS ...


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March 18, 2016

Oct 28-9:34 PM

An SRS provides for individuals to have the same

chance or probability of being selected but also

possible group can be selected as well.

an SRS because it would be impossible to

select a group of 5 students over age 21.

The "give-away" is that we started by the selecting by

Oct 28-9:34 PM


selected the blocks and then contacted all the families in the

selected block.


less time to gather the information from "blocks" of families

rather than travel all over the subdivision to seek out the

randomly selected families for the survey.


19

March 18, 2016

Oct 28-9:34 PM


selected the rectangles and then examined all the trees in the

selected rectangle.


less time to gather the information from 20 rectangles of

trees rather than travel all over the forest to seek out the

randomly selected trees for the survey. (plus you would have to

label all of the trees in each rectangle)

Oct 28-9:34 PM

a) The sample result will not be exactly the same should be

very close to the true population proportion. This is sampling

variability. (each sample will have different students and could

have a slightly different result)

SRS of 100 students will provide more data and should

average out closer to the true population proportion.

Larger random samples are better than smaller random samples


20

March 18, 2016

Oct 28-9:34 PM

a) The sample result will not be exactly the same should be

very close to the true population proportion. This is sampling

variability. (each sample will have different students and could

have a slightly different result)

SRS of 100 students will provide more data and should

average out closer to the true population proportion.

Larger random samples are better than smaller random samples

Oct 28-9:34 PM

This survey will yield a result because you wanted to know the

average amount of money spent by the fans on opening day and your

survey does NOT include the "big-spenders". Thus your result should

under-estimate the average amount of money spent by the fans. The

This BIAS is called UNDERCOVERAGE (we did not select anyone from

the $$ seats)


21

March 18, 2016

Oct 28-9:34 PM

This survey should yield a

because it does not include any students that are

given a ride to school by their parents or that drive

to school themselves. I believe the survey will

over-estimate of the time that students get

out of bed before school starts because the

busses take longer to transport students to school

(they have to stop for everyone on the route).

The estimate will be

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Daily Agenda - Kenston Local Schoolskenstonlocal.org/baugher/wp-content/uploads/2015/06/Chapter-4... · Daily Agenda 3. Notes 4.2 Quiz ... Seed Calculator with number 555 (just for