1. The problem provides data of doses of NPK 13:6:27 fertilizer (Kg per tree) for different varieties and repetitions. 2. To analyze or model this data, one might want to find relationships or trends, such as fitting a function to dose vs. yield or other variables. 3. Since no explicit question is asked, let's demonstrate how to fit a linear model for one variety and repetition as an example. 4. Consider the variety "Marihat" with repetition 1, doses: $[1.5, 1.75, 2, 2.25, 2.5]$ and corresponding values: $[0.74, 0.84, 1.3, 1.6, 1.8]$. 5. The linear model formula is $y = mx + b$, where $m$ is slope and $b$ is intercept. 6. Calculate slope $m$ using the formula: $$m = \frac{n\sum xy - \sum x \sum y}{n\sum x^2 - (\sum x)^2}$$ 7. Calculate intercept $b$ using: $$b = \frac{\sum y - m \sum x}{n}$$ 8. Compute sums: $\sum x = 1.5 + 1.75 + 2 + 2.25 + 2.5 = 9.999999999999998 \approx 10$ $\sum y = 0.74 + 0.84 + 1.3 + 1.6 + 1.8 = 6.28$ $\sum xy = (1.5)(0.74) + (1.75)(0.84) + (2)(1.3) + (2.25)(1.6) + (2.5)(1.8) = 11.995$ $\sum x^2 = 1.5^2 + 1.75^2 + 2^2 + 2.25^2 + 2.5^2 = 20.375$ $n = 5$ 9. Calculate slope: $$m = \frac{5 \times 11.995 - 10 \times 6.28}{5 \times 20.375 - 10^2} = \frac{59.975 - 62.8}{101.875 - 100} = \frac{-2.825}{1.875} = -1.5067$$ 10. Calculate intercept: $$b = \frac{6.28 - (-1.5067) \times 10}{5} = \frac{6.28 + 15.067}{5} = \frac{21.347}{5} = 4.2694$$ 11. So the linear model is: $$y = -1.5067x + 4.2694$$ 12. This model can be used to estimate values within the dose range for Marihat variety, repetition 1. Final answer: $$y = -1.5067x + 4.2694$$