RK

Rehema Kemunto

My work spans behavioral economics, operational research, and product analytics. I've tested pricing psychology across 185,000+ transactions and quantified weather's impact on transit demand to save £23K/month.

See the work

Technical Skills

Hypothesis Testing
Bayesian Inference
Regression Analysis
Python
R
SQL
Power BI
Looker Studio
Root Cause Analysis
Django

Projects

A record of questions I asked, methods I used and what I actually found.

Left-Digit Bias Audit: Pricing Psychology

Does X.99 pricing actually work? I analyzed 185,000+ transactions to find out.

Finding: It works for some products, not others. Phones showed a +5.16% sales lift with X.99 pricing (p<0.001). Laptops showed no effect at all. Pricing psychology is category-specific, not a universal lever.

Impact: Retailers applying charm pricing uniformly are leaving money on the table in some categories and wasting it in others. This analysis tells you exactly which is which.

Python Mann-Whitney U Test Non-Parametric Statistics Behavioral Economics
View on GitHub

Beyond the Treadmill: A Multivariate Analysis of Exercise and Mental Health

Does exercise actually help depression, or are we missing the bigger picture in the data?

Finding: Exercise is a significant predictor of depression (p = 0.014) but explains only 0.25% of variance in isolation. A whole-person model revealed Age and BMI are mathematically stronger predictors. Clustering exposed a High-Risk group that exercises maximally yet shows 67.5% clinical depression prevalence. Three categorical hypothesis tests failing in sequence is not a dead end — it is proof that continuous data must not be bucketed.

Impact: Demolished the simplistic "exercise equals happiness" narrative with real-world NHANES data (n = 2,004). The methodological finding - that forcing continuous data into categories destroys statistical signal - is the most transferable result.

R K-Means Clustering Multiple Regression Hypothesis Testing
View on GitHub

Weather Impact Analysis: Hypothesis Testing

How much does weather actually affect public transit demand?

Finding: Weather accounts for 38.7% of demand variance across 17,400+ hourly observations. The pattern is consistent and predictable enough to schedule around.

Impact: Turned a vague operational problem into a staffing model. Dynamic scheduling based on weather forecasts saved £23K/month. Rigorous assumption-checking is what made the result trustworthy enough to act on.

Python Welch's t-test Hypothesis Testing Operations Research
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Bayesian A/B Testing: E-Commerce Optimization

Does reducing product density improve conversions? And how confident can I be in the answer?

Finding: 98% probability that lower product density improves conversion rates. The sensitivity analysis held across multiple priors, meaning the result is not fragile to starting assumptions.

Impact: A frequentist test tells you whether the result is significant. This tells you the probability that the decision is correct. This matters for real-time business decisions.

Python Bayesian Statistics Beta-Binomial Model Monte Carlo Simulation
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Polo Shirt Product Performance Analysis

Why is one product returning at 48%? That is not normal.

Finding: Segmenting 5,000+ transactions by color, size, and timeframe isolated the problem to a single variant: the Black colorway had a manufacturing defect. One color, one quality failure, the entire return rate explained.

Impact: The problem was invisible in aggregate and visible the moment you segment correctly. Fixing the defect is projected to improve profit margin by 23%.

SQL Power BI Root Cause Analysis Statistical Validation
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Retail Operations and Finance Optimization

Where are the bottlenecks in this $66.31M operation? Why are fulfillment times inconsistent?

Finding: Specific warehouses were responsible for 40% of delays. Not a systemic failure across the operation. One identifiable root cause, isolated through segmentation.

Impact: Reduced manual data processing by 60%. More importantly, the question changed from "why are things slow?" to "warehouse X has a process problem, here is what needs to change."

SQL Power BI Google Apps Script Root Cause Analysis
View on GitHub

Education

BSc in Mathematics

University of Nairobi

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