* Columns correspond to Variables
* Rows correspond to individuals
* Rows are often called observations or cases
* The number of rows is traditionally denoted by n
* In the bar chart the height of each bar is proportional to the count (or percent) in each category * In the pie chart the area of each piece is proportional to the percent of individuals in each category * Pareto chart when the categories are sorted by frequency * Pie charts are less useful than bar charts if we want to compare actual counts (easier to compare bars than angles of wedges) * The area occupied by a part of the graph/chart that displays data should be proportional to the amount of data it represents * Categorical variable: the category with the highest frequency * Numerical variable: location of a major peak of the distribution * Mean = center of mass = the balance point

* Define first quartile to be the median of the observations below the median * Define third quartile to be the median of the observations above the median * The interquartile range IQR is Q3 - Q1

*
* Coefficient of Variation: defined as the ratio of SD to the mean, has no units, usually is expressed as a percentage, indicates how large SD is relative to the mean * IQR: Robust measure (same as the median), Has the same units as the observations * S: NOT a robust measure (same as the mean), Has the same units as the observations, s=0 if and only if all the observations are equal * The central box spans the quartiles Q1 and Q3.

* The line in the box marks the median M.
* The whiskers extend out to the smallest and largest observations * A density describes the overall pattern of a distribution. The area under the curve and above any range of values is the relative frequency of all observations that fall in that range. * Uniform Density = flat

* A mode of a density curve is a peak point of the curve
* The median of a density curve...

...QMS 202 Quiz #1 Crib Sheet
Inferential statistics is the process of using sample results to draw conclusions about the characteristics of a population
Mean: Standard Deviation:
If population of individual measurements is normal, x is normal
Sample size (n ≥ 30), x is normal
To convert any random variable X to standardized normal random variable Z:
To determine the percentile using z-score, use normalcdf(lower, upper, mean, standard deviation)....

...Chapter 3
Standard units tell you how many standard deviations above or below average a data value is
standard units = (actual value – average)/SD
actual value = average + (SD x standard units). Standard units are denoted by Z.
Chapter 8
Complement rule: P(A) = 1 – P(A doesn't happen)
Multiplication rule:
P(A and B both happen) = P(A) x P(B given A happened)
Q. 5 random components removed one at a time from box containing 5 defective and twenty working. What is chance of selecting...

...Random Sample: each member of the population has the same chance of being selected
Representative Sample: characteristics should represent those of the target population without bias
Observational Study: no intervention by the investigator, no treatment imposed
Experimental Study: investigator has some control over the determinant
Variables:
Categorical – each observation falls into a finite number of groups
Nominal: named variables with no implied order e.g. personality...

...Statistics – body of principles and procedures developed for collecting, summarizing, and interpreting data
Chapter 1
– Distribution – describes what values the variable takes and how often
– Pie Charts/Bar Graphs – categorical
– Histograms/Stem plots – quantitative
– Data set has info on number of individuals
– For each individual, data gives values for variables
– When looking at graph…
o Center – middle of data
o Shape – symmetry or skewed
o Spread – range of data
Chapter 5...

...RESIDES (PERSON_NAME, STREET, CITY, STATE)WORKS (PERSON_NAME, COMPANY_NAME, SALARY)ADDRESS (COMPANY_NAME, CITY, STATE, ZIP)MANAGES (PERSON_NAME, MANAGER_NAME)
3. Find all employees who live in the same city and street as their manager (3 pts)
SELECT R.PERSON_NAME, M.MANAGER_NAME, R.STREET, R.CITY, R2.STREET, R2.CITY
FROM RESIDES R, MANAGES M, RESIDES R2
WHERE R.PERSON_NAME = M.PERSON_NAME AND M.MANAGER_NAME =
R2.PERSON_NAME AND R.STREET = R2.STREET AND R.CITY = R2.CITY
4. Find all persons...

...Accrued Interest = x Nominal Return = Real Return = – 1 Real rate of return Compounding = rnominal-inflation rate
Current yield = The invoice price is the reported price plus accrued interest The ask price is 101.125 percent of par, so the invoice price is: $1,011.25 + (1/2 $50) = $1,036.25
Effective annual rate on a three-month T-bill: Optimal capital allocation: Y= E(rp)- Rf / A(std)^2portfilio
– 1 = (1.02412)4 – 1 = 0.1000 = 10%
Effective annual interest...

...1. The sociological perspective, as a way of thinking about the world, includes the sociological imagination from C. Wright Mills, the beginner’s mind from Bernard McGrane, and the idea of culture shock from anthropology. Explain what all three of these concepts have in common.
Response: All three of these concepts have in common are the idea of breaking down social barriers to gain a different perspective on culture people and behaviors. When a person is in a new area where the...