If $\frac{{\mathrm{x}}^2}{\text{⨍(4a)}}+\frac{{\mathrm{y}}^2}{{\text{⨍(a}}^2\text{-5)}}=1$ represents an ellipse with major axis as y-axis and $\text{⨍}$ is decreasing function then$\mathrm{a}\in \left(\infty ,1\right)$