From Jeoprady Review Flashcards
3 teachers have bet as to whether any of their students scores higher that the other 2 classes.
Which TOOL should they use?
ANOVA
3 or more groups of data to measure statistical diff.
Which TOOL would use:
Minimize production Costs of 2 products that share an assembly line while meeting Marketing Demands.
Linear Programming
Takes multiple items that share resources and comes up with SINGLE best answer for production mix
Linear Regression can help us Discover which? ( Causation, Correlation, Variation, Probability)
Correlation (CO - Relation)
Which Tool?
Do ice cream sales go up when the temp is higher? (Linear Prog., Linear Regression, Cross-over Analysis, Cluster Analysis)
correltion being tested…. LINEAR Regression does the best
Cluster Analysis helps the Marketing Department do which?
- Group customers
- forecast sales
- choose new products
- schedule production
Group Customers (market segmentation)
Which DISTRIBUTION has Mean and Median that NEARLY equal to ZERO?
(multimodal, pareto, normal, binary)
NORMAL (bell-curve)
Which Tool?
Launching new product, how munch money will be spent before Gross Income is POSITIVE?
(linear programming, forecasting, break-even analysis, decision analysis)
Break Even Analysis
Tool?
analyze new factory set up without building the factory…
Simulation
Temps in sample remain within Consistent Range between HIGH and LOW..
HOMOscedasticity (uniform scattering)
Consistent as move across X
Store sales are $100k per month and within a St Dev of $10k.. What is the probability that sales will be less than $70k? (0.5, 3.5, 17, 33)
MEAN = 100k
St Dev - 10k
Know in normal dist/bell curve… 3 st dev to left (lower than) average or mean… 99% all events in it,, half of 1% is 0.5%
Tool?
Customer wants to choose 1 of 3 vendors based on forecasted demand for the next year..
(cluster, decision analysis, crossover, anova)
Classic CROSS OVER - which most economical choice?
Housing prices forecasted by size of home and lot and # bedrooms/bathrooms, which are related to each other?
(multiple regression, time series, chi-square, breakeven)
Multiple Regression (4 different X variable to determine the Y variable)
Manager concerned the Sales Forecast is too high because the Economy is slowing down.
(cyclicality, trend, random variation, seasonality)
Cyclicality (business cycle)
Describes the level of Variation is a set of data..
Standard Deviation (how much varied around the mean)
Which reveals the Prob of being wrong if we Reject the Null Hypothesis?
P-Value (prob that null is actually true)
Chi-square help understand which question?
Look at diff categories of events… so …
Police interaction deaths is an example of how can be used
Difference between frequency of event occurrences
Describes fact that Today’s weather is related to Yesterday’s weather.
Autocorrelation… the data points related to each other rather than just to the variables… typically make an adjustment
Z = (-) 1 … what is the probability that Sales will be at or below this level?
To the left.. 1 st deviation… .17
Which part of a Linear Regression is the Independent Variable?
(Y, X, F, P-Value)
Get to chose value of Independent
X Variable is correct answer
Housing prices, forecast by Size of Home/Lot and Number of Bedrooms/Bathrooms, which are RELATED to each other…
(Heteroscedasticity, homoscedasticity, autocorrelation, collinearity)
Collinearity… variable are related and lines are Colinear
Which of these uses Normal Distribution to watch for UNUSUAL occurrences..
Quality Control
R squared value
R x R… no negative values possible and must be between ZERO and 1
