From Jeoprady Review Flashcards

1
Q

3 teachers have bet as to whether any of their students scores higher that the other 2 classes.

Which TOOL should they use?

A

ANOVA

3 or more groups of data to measure statistical diff.

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2
Q

Which TOOL would use:

Minimize production Costs of 2 products that share an assembly line while meeting Marketing Demands.

A

Linear Programming

Takes multiple items that share resources and comes up with SINGLE best answer for production mix

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3
Q

Linear Regression can help us Discover which? ( Causation, Correlation, Variation, Probability)

A

Correlation (CO - Relation)

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4
Q

Which Tool?

Do ice cream sales go up when the temp is higher? (Linear Prog., Linear Regression, Cross-over Analysis, Cluster Analysis)

A

correltion being tested…. LINEAR Regression does the best

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5
Q

Cluster Analysis helps the Marketing Department do which?

  • Group customers
  • forecast sales
  • choose new products
  • schedule production
A

Group Customers (market segmentation)

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6
Q

Which DISTRIBUTION has Mean and Median that NEARLY equal to ZERO?
(multimodal, pareto, normal, binary)

A

NORMAL (bell-curve)

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7
Q

Which Tool?

Launching new product, how munch money will be spent before Gross Income is POSITIVE?

(linear programming, forecasting, break-even analysis, decision analysis)

A

Break Even Analysis

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8
Q

Tool?

analyze new factory set up without building the factory…

A

Simulation

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9
Q

Temps in sample remain within Consistent Range between HIGH and LOW..

A

HOMOscedasticity (uniform scattering)

Consistent as move across X

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10
Q

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)

A

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%

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11
Q

Tool?

Customer wants to choose 1 of 3 vendors based on forecasted demand for the next year..
(cluster, decision analysis, crossover, anova)

A

Classic CROSS OVER - which most economical choice?

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12
Q

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)

A

Multiple Regression (4 different X variable to determine the Y variable)

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13
Q

Manager concerned the Sales Forecast is too high because the Economy is slowing down.
(cyclicality, trend, random variation, seasonality)

A

Cyclicality (business cycle)

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14
Q

Describes the level of Variation is a set of data..

A

Standard Deviation (how much varied around the mean)

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15
Q

Which reveals the Prob of being wrong if we Reject the Null Hypothesis?

A

P-Value (prob that null is actually true)

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16
Q

Chi-square help understand which question?

A

Look at diff categories of events… so …

Police interaction deaths is an example of how can be used

Difference between frequency of event occurrences

17
Q

Describes fact that Today’s weather is related to Yesterday’s weather.

A

Autocorrelation… the data points related to each other rather than just to the variables… typically make an adjustment

18
Q

Z = (-) 1 … what is the probability that Sales will be at or below this level?

A

To the left.. 1 st deviation… .17

19
Q

Which part of a Linear Regression is the Independent Variable?
(Y, X, F, P-Value)

A

Get to chose value of Independent

X Variable is correct answer

20
Q

Housing prices, forecast by Size of Home/Lot and Number of Bedrooms/Bathrooms, which are RELATED to each other…
(Heteroscedasticity, homoscedasticity, autocorrelation, collinearity)

A

Collinearity… variable are related and lines are Colinear

21
Q

Which of these uses Normal Distribution to watch for UNUSUAL occurrences..

A

Quality Control

22
Q

R squared value

A

R x R… no negative values possible and must be between ZERO and 1