Statistics 211
Use postal zip code to divide state into regions. Pick a random sample of 10 zip code areas and then include all the businesses in each selected zip code area.
Cluster Sample
Send a team of 5 research assistants to bishop street in downtown Hawaii. Let each assistant take a block and interview an employee form each business found. They must get 20.
Convenience Sample
Stratified Sample
Divide the entire population into distinct subgroups called strata. Groups are based on characteristics like age, education level, and income.
Systematic sample
Number all members of the population sequentially. Then, from a starting point selected at random, include every kth member of the population in sample.
Assign each business in the island business directory a number, and then use a random-number table to select the business es to be included in the sample.
Simple random simple
Mound shaped symmetrical
both sides are the same, graph is folded vertically down the middle.
relative frequency
class frequency/ total # of frequencies
Convenience Sample
create a sample by using data from a population that is readily available
time series graph
data plotted in order of occurrence at regular intervals over a period of time
Qualitative Variable
describes an individual by placing the individual into a category or group, such as male or female.
skewed left or skewed right
direction of skewness is to the left or right
Cluster Sample
divide the entire population into pre-existing segments or clusters. The clusters are often geographic. Include every member of each selected cluster cluster in the sample.
class width
largest data value- smallest data value/ desired # of classes
midpoint
lower class limit + upper class limit/ 2
stem and leaf display
method of exploratory data analysis that is used to rank-order and arrange data into groups.
Major field of study
nominal
Simple Random Sample
of n measurements from a population is a subset of the population selected in such a manner that every sample size n from the population has an equal chance of being selected. Use simple random sample from the entire population.
course evaluation scale: Poor, acceptable, good
ordinal
Frequency table
partitions data into classes or intervals and shows how many data values are in each class. The classes or intervals are constructed so that each data value falls into exactly one class
Age of student
ratio
Length of time to complete an exam
ratio
Score on last exam (based on 100 possible points)
ratio
lower class boundaries
subtract .5 from the lower class limits
Use the Island business directory. Number of all businesses. Select a starting place at random, and then use every 50th business listed until you have 100 business.
systematic sample
Population Data
the data from every individual of interest
Sample Data
the data from only some of the individuals of interst
width
the difference between the lower class limit and other lower class limit of the next class
upper class limit
the highest data value that can fit in a class
lower class limit
the lowest data value that can fit in a class.
uniform or rectangular
these terms refer to a histogram in which every class has equal frequency.
circle chart or pie chart
wedges in a circle visually display proportional parts of the total population that share a common characteristic.
2 Ordinal Level
applies data that can be arranged in order. However, differences between data values either cannot be determined or are meaning less
4 Ratio Level
applies to data that can be arranged in order. Data at ratio can have a true zero.
3 Interval Level
applies to data that can be arranged in order. In addition, differences between data values are meaningful.
1 Nominal Level
applies to data that consist of names, labels, or categories. There is no implied criteria.
Individuals
are the people or objects included in the study.
non-sampling error
is the result of poor sample design.
Statistics
is the study of how to collect, organize, analyze, and interrupt numerical information from data.
What is the difference between a class boundary and a class limit? (Select all that apply.)
Class boundaries are values halfway between the upper class limit of one class and the lower class limit of the next. Class limits specify the span of data values that fall within a class. Class boundaries are possible data values. Class boundaries are not possible data values. Class limits are possible data values.
What is the difference between a class boundary and a class limit?
Class limits are possible data values, class boundaries are not possible data values, class limits specify the span of data values, class boundaries are values halfway between the upper class limit of one upper class limit and the lower class limit next.
Group the businesses according to type: medical, shipping, retail, manufacturing, financial, construction, restaurant, hotel, tourism, and other.
Stratified Sample example
Sampling error
a difference between measurements from a sample and corresponding measurements from the respective population.
Population Parameter
a numerical measure that describes an aspect of a population
Sample Statistic
a numerical measure that describes an aspect of a sample
upper class boundaries
add .5 to the upper class limits
Quantitative Variable
has a value or numerical measurement for which operations such as addition or averaging make sense.
bimodal
histogram in which the two classes with the largest frequencies are separated by at least one class.
Outliers
in a data set are the data values that are very different from the other measures in the data set.
Time of first class
interval
Inferential Statistics
involves methods of using information from a sample to draw conclusions regarding the population.
Descriptive Statistics
involves methods or organizing, picturing, and summarizing information from samples or populations.
Pareto Chart
is a bar graph which the bar height represents frequency of an event. left to right in order from decreasing height
Variable
is a characteristic of the individual to be measured or observed
