1. The problem is to understand the concept of a Completely Randomized Design (CRD) in experimental design. 2. A Completely Randomized Design is a type of experimental design where all experimental units are assigned to treatments completely at random. 3. The main formula used in analyzing CRD is the ANOVA (Analysis of Variance) model: $$Y_{ij} = \mu + \tau_i + \epsilon_{ij}$$ where: - $Y_{ij}$ is the response from the $j^{th}$ unit receiving treatment $i$, - $\mu$ is the overall mean, - $\tau_i$ is the effect of treatment $i$, - $\epsilon_{ij}$ is the random error term. 4. Important rules: - Treatments are assigned randomly to experimental units. - Errors $\epsilon_{ij}$ are independent and normally distributed with mean zero and constant variance. 5. The analysis involves partitioning the total variation into variation due to treatments and error, then testing if treatment effects are significant. 6. This design is simple and effective when experimental units are homogeneous. Final answer: A Completely Randomized Design randomly assigns treatments to units and analyzes data using ANOVA model $$Y_{ij} = \mu + \tau_i + \epsilon_{ij}$$ to test treatment effects.