Engineering & Statistics Calculator
Guided data analysis · Excel/CSV import · statistics, quality, graphing and scientific math · User Manual →
First visit? Load a worked example in Guided Analysis, choose your question, then run the analysis. Review assumptions before interpreting a result.
Read the quick startDistribution Lookup Tables
Browse the reference tables used in the simulated exams. Choose a table, enter your lookup keys, and select Find to highlight the matching row, column and cell.
Table values are rounded and cover a fixed grid. This workspace requires exact tabulated keys; it does not interpolate or substitute degrees of freedom. For values outside the tables, use the .
CONNECT QUALITY TO BUSINESS RESULTS
Measure the cost. Verify the benefit.
Find the largest quality losses, evaluate an improvement case, and track documented benefits without treating every improvement as cash savings.
- 1 Establish cost & volume evidence
- 2 Compare the improvement case
- 3 Track actuals & verification
Project inputs
1 · Quality cost ledger
Enter the headers below. Categories: Prevention, Appraisal, Internal failure, External failure. Line cost = Quantity × UnitCost. Use quantities such as scrap tonnes or rework/downtime hours and matching rates. Events are separately allocated counts, not quantities.
2 · Production volume & revenue
One row per period/product. Positive volume in one consistent production unit. Blank revenue means unknown; zero means zero. Periods follow table order. A baseline rate for each product adjusts comparisons to the current volume and product mix.
Import from Guided Analysis
Import Excel/CSV there first. Rename/reorder the columns to exactly match the target table headers. Explicit exclusions and the exact category filter apply. This copies a snapshot, with provenance in the report.
Directly entered tables.
3 · Projected improvement business case
Standalone annual forecast, not calculated or verified from the cost reduction. Year 0 implementation outlay; constant annual benefits/costs over the horizon. Only cash savings enter cash NPV, ROI and payback.
Low/base/high scenarios vary gross cash benefit only; costs stay fixed. Use a rate consistent with your nominal/real cash-flow basis. No tax, inflation, terminal value or borrowing model is applied.
4 · Benefit & cost verification register
Optional. Types: Cash savings, Cost avoidance, Released capacity, Implementation cost, Recurring cost. Status: Projected, Realized, Verified. Keep one unique ID per benefit/cost and update its status; do not duplicate it across stages. Amounts are period totals in the selected currency; capacity is a noncash valuation.
Verified entries require an owner, evidence reference, valid nonfuture date (YYYY-MM-DD) and basis/verification notes. Negative benefit amounts record reversals; cost amounts must be nonnegative. Verification is user-recorded, not authenticated or approved by this tool.
Session-only, local calculations. Up to 2,000 rows / 1 MB per table. Save before closing. Do not add ledger cost reductions, forecasts and register benefits together.
Quality economics
Load an example or enter your cost and production tables.
Volume, product mix & period tracking
Projected business case — cash only
Base-case annual cash flows
Recorded benefits — separate from projections
Interpretation & review notes
UNDERSTAND VARIATION · MONITOR CHANGE
Know when your process changes.
Establish a baseline, monitor new observations against fixed limits, and distinguish process stability from specification compliance.
- 1 Choose the sampling model
- 2 Review and freeze a baseline
- 3 Investigate signals and capability
Data & chart design
Reuse data from Guided Analysis
Import Excel/CSV and edit it in Guided Analysis first. Choose columns in the order required above. Current explicit exclusions and the exact category filter are applied; blanks are rejected. The copy is a snapshot.
Select “Show active dataset” to see its columns.
Separate columns with commas, tabs or spaces. Up to 10,000 values and 250,000 characters. Missing cells are rejected; blank lines are ignored. Preserve chronological order.
Pasted measurements
Only these first rows estimate limits. Later rows are monitoring observations. Include at least 20 representative baseline rows when possible.
No frozen baseline. Estimate from the first rows.
Freezing keeps only the later monitoring rows in the editor; baseline data remain in the snapshot. With a frozen baseline, paste the complete monitoring sequence each time. Save before closing; there is no automatic storage.
Specification compliance & capability
Optional engineering limits apply to individual measurements, not subgroup means. Capability estimates use the baseline only.
Process evidence
Choose a chart and load its example to get started.
Assumptions & next steps
Point values, limits & signal reasons
Each chart shows the first 200 table rows here. Download the report or CSV for all rows. No observations are removed automatically.
FROM DATA TO A DECISION
Start with your question.
Bring your data, choose what you need to learn, and work through the evidence with clear assumptions and next steps.
- 1 Bring & review data
- 2 Define your question
- 3 Interpret & take action
1 · Import or restore data
Files stay in this browser. Up to 10 MB per file; 10,000 rows, 40 columns and 100,000 cells per dataset. Use a period for decimals. Older .xls files must be saved as .xlsx or CSV.
Add a table or try a worked example. Up to five datasets can share this session.
Review and edit data · row exclusions & import notes
Edit cells directly. Uncheck a row to exclude it explicitly; changing data invalidates results. Row order is preserved. Duplicate rows are flagged for review and retained.
Dataset edit history
Datasets are held in memory for this session. Save workspace to keep data, edits, exclusions and analysis settings before reloading. Restoring a project adds its datasets; it never runs an analysis automatically.
2 · Define your question
For two groups, difference = comparison minus reference. With three or more groups, ANOVA tests for any mean difference.
Choose this threshold before reviewing results. All t tests use two-sided inference.
Filter rows and handle missing values
Only blanks in the selected analysis columns are treated as missing. Invalid numbers block analysis. Paired rows are excluded together.
Guidance follows your question and study design. It does not automatically certify assumptions or choose a method using a normality-test p-value.
3 · Understand the evidence
Import data, select your columns and review the suggested method.
Assumptions & method notes
What to do next
Row exclusions
The report includes inputs, settings, exclusions, interpretation and next steps. Full results become unavailable when inputs change.
Analyze your data
Decimal point: period. Separate cells with tabs, commas, semicolons, or spaces. No headers or thousands separators. Blank lines are ignored; invalid or empty cells are reported.
Calculations run in your browser. This workspace does not upload or save your dataset.
Results
Choose an analysis, paste data, or load an example.
Methods, assumptions & references
Intervals for a mean use Student’s t. Regression fits ordinary least squares with an intercept; residual standard error uses n − 2 degrees of freedom. ANOVA is the classical equal-variance F test. Chi-square uses Pearson’s statistic without continuity correction and reports every expected cell count.
Capability uses s for Pp/Ppk and MR̄ ÷ 1.128 for Cp/Cpk. I-MR limits are estimated from the entered sequence; only points beyond three-sigma limits are flagged. Review stability, independence and distribution shape before interpreting capability. Specification limits are engineering requirements, not control limits.
Graph & explore
Use x, pi, sin(x), abs(x), sqrt(x), log(x), or a piecewise expression such as x < 0 ? -x : x.
Table settings (function mode)
Graph window
Draw the example or enter your own expressions.
Numerical analysis (Cartesian functions)
Zeros need a sign-changing bracket. A minimum/maximum search assumes one extremum within the interval. Plot sampling can miss narrow features; check the window and numerical result.
Math workspace
Lists: L1 = [1,2,3]. Matrices: A = [1,2;3,4]. Complex: sqrt(-1), (2+3i)*(1-i). Units: 25.4 mm to inch. Last result: Ans. Variables are shared with graphing and programs for this session.
Calculation tape
Evaluate expressions using the examples or function catalog.
Syntax & numerical tools
Use * for multiplication and ^ for powers. ln(x) and log(x) are natural logarithms; log10(x) is base 10. Complex results use a + bi. arg(z) returns radians. RAD/DEG applies to trigonometric functions, their inverses, atan2, and the nDeriv/fnInt/solve/seq helpers. Complex arg/angle remains in radians.
nDeriv("x^3",2), fnInt("sin(x)",0,pi), solve("x^2-2",0,2), seq("n^2",1,10), rref([1,2,3;2,1,4]).
Matrix/list indexing and user-defined functions are not enabled. Use whole-array operations. Large operations are bounded; a timeout resets workspace variables to keep the interface responsive.
Time value of money
Money received is positive; money paid is negative. N counts payment periods, not years. The selected unknown is ignored until solved.
Financial results
Cash flows & rate conversion
In Lists & Matrices, use npv(0.10,[-1000,400,400,400]) for a 10% per-period discount rate. The first cash flow occurs at time zero. Use irr([-1000,400,400,400],0,1) for the decimal periodic IRR within a bracket. IRR can have multiple roots or no root.
eff(6,12) converts 6% annual nominal interest, compounded monthly, into an annual effective percentage. nom(6.1678,12) performs the reverse conversion. TVM uses an annual nominal percentage; NPV/IRR use decimal rates per cash-flow period.
Calculation programs
Programs run locally in an isolated worker. Maximum 500 lines and 10,000 execution steps. A timeout resets shared variables.
Program output
Supported programming subset
Assignments (value→A, value->A, or A=value), Disp expression, ClrHome, For(I,start,end,step), While condition, If condition / Then / Else / End, and Stop. Every control block requires End, including If.
Use the math-workspace function catalog. This is a documented calculation-language subset, not a TI-BASIC emulator: device I/O, key events, labels/Goto, graphical commands, tokenized .8xp files and installed TI apps are not supported.
History tape
Click any entry to reuse it. Ans holds the last result.