LEARN · EXPLAIN · REVISE

Under independence, find E11.

Read the idea, work independently, then explain what changed.

TOPIC 01

Statistical analysis of paired data: mixed review

A mixed assessment: identify the method, justify it and revise your reasoning.

Use one hint at a time. A correction explains what changed, not just the final answer.

01 / Foundation#Your turn

O=\begin{pmatrix}70&35\\35&70\end{pmatrix}

Observations must be independent; expected counts support the supplied large-sample approximation. Rejection is evidence of association, not causation.

Skills and prerequisite lessons

Working and explanation

BUILD THE REASONING

Hint 1

Use the paired-data summaries, preserving which observations belong together.

Hint 2

Use this intermediate relation.

E_{11}=R_1C_1/N

Worked solution

The requested value is 52.5.

Checks and common pitfalls: Use both relevant margins and the full sample size.

Think first. Reveal a hint when the class is ready.

Teacher preparation and assessment