CFA resources
Investment analysis, valuation and portfolio management
- Worked examples
A one-sided test with an opposite-sign statistic
Use the planned tail when the estimate points away from the alternative.
- Common mistakes
Treating a p-value as the probability of the null
Repair the reversal from a model-conditional tail area to a hypothesis probability.
- Practice
Practice: tails, uncertainty and error budgets
Check test direction, independent-mean precision and family corrections with explained answers.
- Worked examples
Sample size and mean-estimation precision
Calculate the sample-size change needed to halve standard error under a fixed-variance model.
- Templates

Statistical test research log
Download a structured CSV for hypotheses, selection, uncertainty and family treatment.
- Concepts
Sample standard deviation versus standard error
Explain which variation each statistic describes before comparing magnitudes.
- Formulas
Standard error of an independent mean
Distinguish uncertainty of a mean from variability of individual observations.
- Concepts
Statistical significance and effect size
Read magnitude and uncertainty before assigning practical meaning to a threshold crossing.
- Formulas
Normal-test p-values by direction
Calculate upper, lower and two-sided tails for a standard-normal statistic.
- Lessons
Designing and reporting a hypothesis test
Connect the research question, null model, test direction and reported result.
- Lessons
Ordinary annuity and annuity-due timing
Place equal payments at the correct dates before applying the value factor.
- Lessons
Balance-sheet assets, liabilities and equity
Read the accounting equation and distinguish recognised balances from a complete business valuation.
- Lessons
Bond prices and yields: understanding the inverse relationship
Learn why a fixed-rate bond’s price changes when the market yield changes.
- Lessons
Cash conversion cycle and its flow bases
Match inventory, receivables and payables with the flows and period length used to calculate their days.
- Lessons
Reading a common-size balance sheet
Scale statement items by total assets while preserving accounting and measurement context.
- Lessons
Default probability and credit loss severity
Separate the likelihood of default from the loss conditional on default.
- Lessons
Discounting cash flows with consistent time periods
Match cash-flow timing, rate conventions and time-zero signs.
- Lessons
Reconciling DuPont analysis to return on equity
Use consistent period and average-balance inputs to reconstruct the direct return ratio.
- Lessons
Designing engagement objectives and escalation decisions
Build an objective, evidence trail and conditional next action for an issuer dialogue.
- Lessons
Economic order quantity and the ordering-holding trade-off
Inspect the deterministic cost objective before using the square-root order quantity.
- Lessons
Specifying an exclusion rule that can be checked
Define the activity, metric, threshold, data source and treatment of missing information.
- Lessons
Liquidity ratios and the quality of current assets
Compare defined numerators while retaining timing, collectability and financing context.
- Lessons
Checking probabilities and a complete scenario partition
Check individual bounds, overlaps and the sum across mutually exclusive exhaustive scenarios.
- Lessons
Checking a two-stage probability tree
Check each conditional split, path product and terminal probability.
- Lessons
Nominal and effective interest rates
Compare quoted annual rates only after identifying the compounding convention.
- Lessons
Screening constraints and the feasible portfolio set
Separate portfolio eligibility constraints from return estimates and realised performance.
- Lessons
Early-payment discounts and the additional credit period
Separate invoice timing, the discount amount and the cost of financing a discounted payment.
- Lessons
Choosing a common date for cash-flow values
Move differently dated cash flows to the same date before adding their values.
- Common mistakes
Basis points, percentage points and decimal yield changes
Avoid a hundredfold error when entering yield changes in formulas.
- Common mistakes
Why a cash-cycle reduction does not specify cash released
Use each changed component’s own flow base instead of multiplying all days by COGS.
- Common mistakes
Mixing average and ending assets in DuPont analysis
Check that the asset amount cancels between turnover and the equity multiplier.
- Common mistakes
Why dividing an effective annual rate by twelve changes the model
Use the annual growth factor to obtain an equivalent monthly rate.
- Common mistakes
Material nonpublic information during an engagement meeting
Identify the information-handling issue before making a trading recommendation.
- Common mistakes
A rising goodwill percentage does not identify its cause
Separate changes in the numerator from changes in the asset denominator.
- Common mistakes
Recognising a solution versus solving independently
Check what you can produce before viewing the worked answer.
- Common mistakes
Why P(A given B) differs from P(B given A)
Recover the joint probability, then divide by the probability of the new condition.
- Common mistakes
Variance in percentage units and decimal-return units
Account for the squared scale factor when converting variance.
- Study plans
Restarting finance exam study after a break
Use a short diagnostic to distinguish forgotten material from unfinished material.
- Study plans
Building a finance exam retake plan
Separate knowledge gaps, execution errors and time pressure before choosing new work.
- Study plans
A study plan for variable work shifts
Assign tasks to flexible block types when the same weekday is not always available.