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GSEB Class 12 Statistics Marvel Paper 2: Section F Solutions (Q57 & Q58)

Welcome back to our 13-Paper Marvel Solution Series! In our last post, we mastered the basics of Section F. Today, we dive into Marvel Paper 2, focusing on the two heavy-hitters of Statistics: Linear Correlation and Rank Correlation.

Even though these are the same chapters as Paper 1, the sums in Paper 2 often involve larger numbers or “tied ranks,” which can easily lead to calculation errors if you aren’t careful.

Deep Dive: Marvel Paper 2 (Q57 & Q58)

Question 57: Linear Correlation (Karl Pearson’s Method)

In Paper 2, Q57 tests your ability to handle the $uv$ method (Shortcut Method). When the values of $X$ and $Y$ are large, using  becomes tedious.

  • What we cover: Selecting the right ‘Assumed Mean’ (A and B).

  • The $uv$ Table: Step-by-step calculation of sum u, sum v, sum u^2, sum v2,and sum uv.

  • Common Mistake: Forgetting to divide by $n$ or misplacing the square root in the final formula.

Question 58: Spearman’s Rank Correlation

Paper 2 often introduces tied ranks. When two or more observations have the same value, the standard formula changes slightly with the addition of the Correction Factor (CF).

  • The CF Formula: CF = {m^3 – m}/{12}

  • Ranking Strategy: How to assign average ranks without getting confused.

  • Final Result: Finding ‘r’ and interpreting the strength of the correlation.

Watch the Full Video Tutorial for Paper 2:

Pro-Tips for Section F Success

  1. Check the Means First: Calculate bar{x} and bar{y} before deciding which formula to use. If they are integers, use the direct method; if not, go for the uv method.

  2. Double-Check \sum d: In Rank Correlation, the sum of differences (sum d) must always be zero. If it’s not, you’ve made a ranking error!

  3. Calculator Speed: Practice using your M+ and MR buttons on the calculator to save time during the 3-hour board exam.

Keep the Momentum Going!

Don’t stop at Paper 2. We are solving all 13 papers to make sure you are the most prepared student in the exam hall.

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