Statistics & Probability / Geometric & Negative Binomial
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LABORATORY 14 · STATISTICS & PROBABILITY

Geometric Distribution, Memoryless Property, and Negative Binomial Stopping Times

Analyze discrete waiting times until success in Bernoulli sequences, test the discrete memoryless property, model Negative Binomial stopping times, and determine the linear scaling of expected waiting time with stopping quota r. Explore interactive statistical sampling, probability models, and empirical regression.

SAMPLE · INFER · CONVERGE

Your virtual statistics laboratory.

EXPECTED TRIAL COUNT E[X]—
SAMPLING TELEMETRY

Ready to sample with Quota r = 1.0.

1.0 successes
Constant success probability p = 0.50

Adjust Quota r, then execute statistical trial.

Probabilistic samples are evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity empirical probability functions.

Statistical assumptions and distribution limits

The memoryless property fails if the success probability p shifts or drifts across sequential trials. The empirical regression of expected trial count against success quota r yields a gradient of m = 2.0000, confirming theoretical waiting time scaling with R² = 1.000000.

Statistical tools & sampling modules.

Sequential Bernoulli Sampler

Generates independent binary trials sequentially until a specified success stopping condition is achieved.

Geometric Waiting Time Counter

Records the number of trials required to achieve the very first success (r = 1).

Memoryless Property Verifier

Evaluates conditional probabilities P(X > s + t | X > s) to confirm discrete memoryless behavior.

Negative Binomial Quota Accumulator

Logs the total number of trials required to observe exactly r successes across Monte Carlo batches.

Pascal-Polya Formulation Engine

Calculates theoretical probabilities under both total-trial and failure-count parameterizations.

Stopping Time Regression Unit

Performs linear regression of expected trial count against success quota r to extract the slope 1/p = 2.000.

FOLLOW THE METHOD

A reason behind every step.

Analyze discrete waiting times until success in Bernoulli sequences, test the discrete memoryless property, model Negative Binomial stopping times, and determine the linear scaling of expected waiting time with stopping quota r. Standardized parameter settings: 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 successes.

01

Calibrate Single-Trial Probability

Set the Bernoulli success probability to p = 0.50 on the simulation dashboard, noting that the theoretical expected trials until first success is 1/p = 2.000.

02

Execute Geometric Trial Series (Quota r = 1)

Simulate 10,000 runs of the experiment with stopping quota r = 1. Record the distribution of total trials required to obtain the initial success.

03

Empirically Verify the Discrete Memoryless Property

Compute conditional frequencies P(X > s + t | X > s) for s = 2 and t = 1, verifying agreement with the unconditional survival probability P(X > t) = (1-p)^t = 0.50.

04

Extend to Negative Binomial Sequences

Configure the stopping engine to halt only when exactly r successes have accumulated, observing that the Negative Binomial variable is the sum of r independent Geometric variables.

05

Step Required Success Quota Across r = 1 to 6

Increment the target quota across standardized settings r ∈ {1, 2, 3, 4, 5, 6}, recording the empirical mean total trials E[X] for each setting.

06

Conduct Linear Regression on Stopping Times

Fit a linear regression model y = mx to the coordinate pairs (x = r, y = E[X]). Confirm that the empirical gradient m = 2.0000 matches theoretical expectation E[X] = r/p.

YOUR NOTEBOOK · 0 OBSERVATIONS

Turn measurements into empirical insight.

See a complete example report ↗

Points are your recorded observations. The solid regression line validates Geometric & Negative Binomial mathematical scaling.

LINEAR REGRESSION FIT · y = mx + b
y = 2.0000 · x
#Success Quota Target r (successes)Expected Trial Count E[X] (Trials E[X])Success Quota rExpected Total Trials E[X]Remove

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CHECK YOUR UNDERSTANDING

Explain what the statistical metrics mean.

For a Bernoulli process with success probability p = 0.50, what is the expected number of trials to achieve r successes?

Which discrete probability distribution uniquely possesses the memoryless property?

In terms of independent Geometric variables W_k, how is the Negative Binomial variable X represented?

How does the variance of a Negative Binomial count variable compare to its mean?