Final Definitions Flashcards
data
facts and figures collected, analyzed, and summarized for presentation and interpretation
data set
all data collected in a particular study
elements
entities on which data are collected
variable
characteristic of interest for the elements
observation
set of measurements obtained for a particular element
categorical data
data that can be grouped by specific categories
quantitative data
data that use numerical values to indicate how much or how many are referred to
categorical variable
variable with categorical data
quantitative variable
variable with quantitative data
population
set of all elements of interest in a particular study
sample
subset of the population
frequency distribution
tabular summary of data showing the number (frequency) of observation in each of several non-overlapping categories or classes
relative frequency distrivution
shows the fraction or proportion of observations belonging in a class (ie 0.38)
relative frequency of a class=frequency of a class/n
percent frequency distribution
summarizes the percent frequency of data for each class ie (38%)
bar chart
graphical display for depicting categorical data summarized in a frequency, relative frequency, or percent frequency distribution
-categorical data: gap between bars
pie chart
presents relative frequency and percent frequency distributions for categorical data
dot plot
show the details of the data and are useful for comparing the distribution of the data for 2 or more variables
histogram
bar chart with no gaps
stem and leaf display
used to show simultaneously the rank order and shape of a distribution of data
variance
measure of variability that utilizes all the data
based on the difference between the value of each observation, xi, and the mean
standard deviation
positive square root of the variance
coefficient of variation
indicates how large the standard deviation is relative to the mean
tree diagram
helps visualize a multi step random expirement
discrete random variable
a random variable that may assume either a finite number of values or an infinite sequence of values ie 0,1,2,3,4 etc
continuous random variable
a random variable that may assume any numerical value in an interval or collection of intervals ie 2.751
probability distribution
describes how probabilities are distributed over the values of the random variable
probability function
provides the probability for each value of the random variable
empirical discrete distribution
the use of the relative frequency method to develop discrete probability distributions leads to an empirical discrete distribution
discrete uniform probability distribution
f(x)=1/n
expected value
mean
binomial experiment
- consists of a sequence of n identical trials
- two outcomes are possible for each trial, success or failure
- probability of success=p, does not change from trial to trial. the probability of failure=1-p, also does not change from trial to trial
- the trials are independent
binomial probability distribution
associated with the discrete random variable, x
sampled population
population from which the sample is drawn
simple random sample
of size n from a finite population of size N is a sample selected such that each possible sample of size n has the same probability of being selected
random sample
of size n from an infinite population is a sample selected such that 1. each element selected comes from the same population
2. each element is selected independently
point estimate
p bar
x/n
sampling distribution
shows distribution of frequencies of a range of different outcomes that could occur
If the number 12.0 appears in a cell, which number might actually be stored there?
11.99
All the columns in a worksheet must have the same width.
T or F?
F
Excel workbooks have the file extension…
.xlsx
Which of the following entries would be considered text?
555-1212
In Excel, a workbook is the same as…
an Excel file
In Excel, column headings are always designated by…
letters
In Excel, row headings are always designated by…
numbers
In Excel, an entire row or column can be hidden for clarity, and then later revealed. T or F
T
A cell reads 3.1E-3. This means the cell contains the number…
0.0031
The ribbon in Excel can be moved to any place on the screen. T or F
F
What symbol must precede every formula?
=
What Excel function adds up all the numbers in a range of data in cells?
SUM
What should you type, exactly, in cell C8 to find the mean cost-per-hour?
=AVERAGE(C2:C7)
What symbol would you add to a cell reference in the formula bar in order to change a relative reference of a cell to an absolute reference?
$
The Excel expression “A2:B3” represents….
a rectangle of cells selected with corners at cells A2 and B3
What must you press to execute the FREQUENCY function
CTRL-SHIFT-ENTER
The Analysis ToolPak makes it possible to quickly generate a histogram from a set of data. Before the Histogram Tool can be used to do this, however, it is necessary to…
choose upper bounds for the bins we want to use and enter them in a column.
How could the formula in cell E2 be altered so that, when copied into cells E3 and E4, the correct counts will be displayed?
=COUNTIF($A$1:$A$15, D2)
Excel can generate a variety of graphs very easily. One type of graph that Excel does not make is a
box plot.
What must be done to get the information in a PivotTable to update after a change is made in the data?
Click “refresh” in the PivotTable Tools menu.
What is the difference between COUNTIF and COUNTIFS?
COUNTIFS can count over multiple ranges and criteria, COUNTIF can only count one range according to one criterion.
How could the formula in cell G3 be altered so that when copied down and across, the correct counts will appear?
=COUNTIFS($B$2:$B$11,G$2,$C$2:$C$11,$F3)
What’s the best kind of chart to use in Excel to visualize the relationship between two numerical variables?
Scatterplot
To measure correlation, Excel has an embedded formula CORREL. Is the following statement true or false?
“Typing =CORREL(A1:A10, B1:B10) will give you the same value as typing in =CORREL(B1:B10, A1:A10).”
T or F
T
