ESTUDYR
ISYE 6644 MIDTERM_1 2025 MULTICHOICE ANSWERED EXAM
QUESTIONS WITH DETAILED RATIONALES
1
What is simulation?
a. A theoretical mathematical proof
b. Imitation of a real-world process or system over time. ← Correct
c. A type of deterministic calculus
d. The act of measuring real systems only
Rationale: Simulation recreates system behavior over time to study performance/decisions.
2
What is a model?
a. Exact replica of hardware
b. High-level representation of the operation of a real-world process or system. ← Correct
c. Only a graphical diagram
d. A physical prototype only
Rationale: Models abstract real systems to make analysis tractable.
3
Is "1 customer shows up and waits in line, and then another, and so on" a discrete or
continuous model?
a. Continuous
b. Discrete ← Correct
c. Stochastic continuous
d. Deterministic continuous
Rationale: Events (individual customers) occur at discrete times.
4
Is an hourly weather prediction for precipitation over time discrete or continuous?
a. Continuous ← Correct
b. Discrete
,ESTUDYR
c. Deterministic discrete
d. None of the above
Rationale: Weather variables vary continuously over time (often modeled in continuous
frameworks).
5
Calls that randomly arrive at a call center: stochastic or deterministic?
a. Stochastic ← Correct
b. Deterministic
c. Static
d. Periodic
Rationale: Arrival times have randomness (e.g., Poisson process).
6
Predicting the voltage given current and resistance (V = IR) is: stochastic or deterministic?
a. Deterministic ← Correct
b. Stochastic
c. Dynamic stochastic
d. None of the above
Rationale: Ohm’s law gives a fixed relationship; no randomness in the formula.
7
Dynamic vs. static models: which is true?
a. Static models have changing relationships over time
b. Dynamic models have changing relationships between variables over time. ← Correct
c. Static models always include randomness
d. Dynamic = no time dimension
Rationale: Dynamic models explicitly include time evolution.
8
, ESTUDYR
Order the three methods to "solve" a model from easiest to hardest:
a. Simulation → Numerical → Analytical
b. Numerical → Analytical → Simulation
c. Analytical (exact) → Numerical (approx) → Simulation (approx with randomness) ← Correct
d. Simulation → Analytical → Numerical
Rationale: Analytical closed forms are simplest when available; simulation is often used when
others fail.
9
Who used early computers in the 1940s for Monte Carlo style simulations of thermonuclear
processes?
a. William Gossett
b. Harry Markowitz
c. Comte de Buffon
d. Ulam, Metropolis, and von Neumann ← Correct
Rationale: These scientists pioneered Monte Carlo methods for the Manhattan Project era
simulations.
10
In surveillance applications (e.g., detecting disease spread), sequential hypothesis tests are
used how?
a. By ignoring data over time
b. Build a null hypothesis, use simulation to approximate its distribution, and reject if
observed data are unlikely under the null. ← Correct
c. Only by analytic closed-form tests
d. By always accepting the null hypothesis
Rationale: Sequential tests compare ongoing data to simulated null distributions to detect
change.
11
A bad pseudorandom number generator (PRNG) visually can show:
a. Uniform scatter with no pattern
b. Perfect Gaussian cloud
ISYE 6644 MIDTERM_1 2025 MULTICHOICE ANSWERED EXAM
QUESTIONS WITH DETAILED RATIONALES
1
What is simulation?
a. A theoretical mathematical proof
b. Imitation of a real-world process or system over time. ← Correct
c. A type of deterministic calculus
d. The act of measuring real systems only
Rationale: Simulation recreates system behavior over time to study performance/decisions.
2
What is a model?
a. Exact replica of hardware
b. High-level representation of the operation of a real-world process or system. ← Correct
c. Only a graphical diagram
d. A physical prototype only
Rationale: Models abstract real systems to make analysis tractable.
3
Is "1 customer shows up and waits in line, and then another, and so on" a discrete or
continuous model?
a. Continuous
b. Discrete ← Correct
c. Stochastic continuous
d. Deterministic continuous
Rationale: Events (individual customers) occur at discrete times.
4
Is an hourly weather prediction for precipitation over time discrete or continuous?
a. Continuous ← Correct
b. Discrete
,ESTUDYR
c. Deterministic discrete
d. None of the above
Rationale: Weather variables vary continuously over time (often modeled in continuous
frameworks).
5
Calls that randomly arrive at a call center: stochastic or deterministic?
a. Stochastic ← Correct
b. Deterministic
c. Static
d. Periodic
Rationale: Arrival times have randomness (e.g., Poisson process).
6
Predicting the voltage given current and resistance (V = IR) is: stochastic or deterministic?
a. Deterministic ← Correct
b. Stochastic
c. Dynamic stochastic
d. None of the above
Rationale: Ohm’s law gives a fixed relationship; no randomness in the formula.
7
Dynamic vs. static models: which is true?
a. Static models have changing relationships over time
b. Dynamic models have changing relationships between variables over time. ← Correct
c. Static models always include randomness
d. Dynamic = no time dimension
Rationale: Dynamic models explicitly include time evolution.
8
, ESTUDYR
Order the three methods to "solve" a model from easiest to hardest:
a. Simulation → Numerical → Analytical
b. Numerical → Analytical → Simulation
c. Analytical (exact) → Numerical (approx) → Simulation (approx with randomness) ← Correct
d. Simulation → Analytical → Numerical
Rationale: Analytical closed forms are simplest when available; simulation is often used when
others fail.
9
Who used early computers in the 1940s for Monte Carlo style simulations of thermonuclear
processes?
a. William Gossett
b. Harry Markowitz
c. Comte de Buffon
d. Ulam, Metropolis, and von Neumann ← Correct
Rationale: These scientists pioneered Monte Carlo methods for the Manhattan Project era
simulations.
10
In surveillance applications (e.g., detecting disease spread), sequential hypothesis tests are
used how?
a. By ignoring data over time
b. Build a null hypothesis, use simulation to approximate its distribution, and reject if
observed data are unlikely under the null. ← Correct
c. Only by analytic closed-form tests
d. By always accepting the null hypothesis
Rationale: Sequential tests compare ongoing data to simulated null distributions to detect
change.
11
A bad pseudorandom number generator (PRNG) visually can show:
a. Uniform scatter with no pattern
b. Perfect Gaussian cloud
