Quantitative Analysis I- Module 1
From the scenarios below, indicate the one that BEST reflects the nominal scale.
Designate males as 0 and females as 1 to compare gender performance on an aptitude test.
Mean can be computed for variables with ordinal-level measurements.
False
This represents the least sophisticated level of measurement.
Nominal scale
The weakness with this scale of data is that we cannot interpret the difference between the ranked values because the actual numbers used are arbitrary.
Ordinal scale
With this data, we are only able to both categorize and rank the data with respect to some characteristic or trait.
Ordinal scale
The branch of statistics that summarizes important aspects of a data set is often referred to as ______ statistics.
descriptive
We generally divide the study of statistics into two branches: ____ and ____.
descriptive, inferential
In a data set, the 25th percentile, or equivalently, the
first quartile
The ___ strategy recommends that the missing values be replaced with some reasonable imputed values.
imputation
A negative skewness coefficient implies that extreme observations are concentrated in the ___tail of the distribution.
left
The average of the absolute differences between the values of the data set and the mean is the
mean absolute deviation.
A positive skewness coefficient implies that extreme observations are concentrated in the ___ tail of the distribution.
right
The function to find the mean of a subset in R is
tapply
The range is the difference between
the largest and the smallest values.
Which of the following values is included in a box plot?
the second quartile
A box plot is constructed using serval different values. Which of the following values included in a box plot:
the smallest value the third quartile the second quartile
The average squared distance of date from their mean is the
variance
A ___ mean is used to calculate the mean of a frequency distribution.
weighted
When a mean is calculated and some observations are given greater importance than others, we refer to this measure of central location as a ______.
weighted mean
For missing ___ variables it is common to impute the most predominant category.
categorical
The term ___ ___relates to the way data tend to cluster around some middle or central value.
central location
Which of the following is an example of descriptive statistics?
Calculate the percent of 2500 U.S. voters in an opinion poll who approve of the President's performance.
___ and ___are among the very first tasks most data analysts perform to gain a better understanding and insights into the data.
Counting, sorting
A quantitative variable is also known as a ___ varible.
numerical
The ___ strategy recommends that observations with missing values be excluded from subsequent analysis.
ommission
Rating products from one to five stars generates ___ data.
ordinal
The ___ is not considered a good measure of dispersion because it focuses solely on the extreme values and ignores every other observation in the sample or the population.
range
The ______ measures the difference between the largest and smallest values in a data set.
range
The pth percentile divides a variable into two parts. What percentage is less than p?
p
the standard deviation of the population set 3,4,5,6 and 8 is
1.72
The pth percentile divides a variable into two parts. What percentage is greater than p?
(100 - p)
Q1- Q2- Q3- Q4-
-25th percentile -50th percentile -75th percentile -100th percentile
Place in order, from beginning to end, the steps to calculate the mean absolute deviation.
1. Calculate the arithmetic mean for the data set 2. find the absolute difference between each value and the mean 3. sum the absolute differences 4. divide by the sample or population size
The mod for the data set: 4,4,5,6,9,9
4 and 9
If the median price for a home is $200,000, then ______ of the homes cost less than $200,000.
50%
The function to find the mean of a subset in Excel is
AVERAGEIF
With data that is measured on this scale, we are able to categorize and rank the data as well as find meaningful differences between observations.
Interval scale
Which of the following statements about the mean absolute deviation (MAD) is MOST accurate?
MAD is denominated in the same units as the original data.
___data allows us to review the range of values for each variable.
Sorting
Which of the following values is included in a box plot?
The first quartile
Which of the following characteristics of interest is a variable?
The number of pizzas ordered from Pizza Hut per day
Which of the following scenarios is an example of the interval scale?
The outside temperature (in degrees Fahrenheit)
A box-and-whisker plot is another name for a
boxplot
The formula for the weighted mean is xx=Σwixi. Using this formula, what is the restrictions on the weights.
They must sum to one.
For a sample, all values in the sample are used to compute the sample mean
True
For a sample, the sum of the deviations from the sample mean is 0.
True
Mean cannot be computed fro variables with nominal-level measurements.
True
Median can be found for variables with ordinal-level measurements.
True
Mode can be found for variables with nominal-level measurements.
True
True or false: The mean is the most widely used measure of central location for quantitative data.
True
Which of the following is not a measure of central location?
Variance
The ___ ___is the primary measure of central location.
arithmetic mean
A ___ helps us identify outliers and skewness in the distribution of a variable.
boxplot
The ___is a measure of central location that divides the observations for a variable in half.
median
