Study Materials for B.Com

State formula, list data transformations, show tables with class boundaries correctly, and box final statistics. Mention whether data is sample or population before variance/SD steps.

Wrong class marks, using inclusive widths inconsistently, early rounding, and confusing mean vs median in skewed data. Always re-sum frequency × midpoint before reporting mean.

Define events, state independence, show complements clearly, and use binomial/Poisson templates with n,p,λ identified. Sketch sample spaces for small counting problems.

Compute covariances stepwise, state r interpretation (strength/direction), and separate correlation from causation in a closing line. For regression, show normal equations or least-squares steps as required.

Tabulate periods, show Laspeyres/Paasche/Fisher only as asked, note base year, and interpret index movement briefly. Link price indices to inflation language when prompts ask for meaning.

Practise standard error setup, confidence interval wording, and z vs t rule of thumb. Write interpretation sentences (“we are 95% confident…”) separate from the numeric interval.

Choose range vs quartile deviation vs SD based on the prompt, show mean deviation steps if asked, and comment on relative dispersion (coefficient of variation) when comparing series.