Would be grateful if I get help

[tex]\\ \sf\longmapsto 72^{\frac{3}{4}}[/tex]
[tex]\\ \sf\longmapsto 72^{\frac{1}{4}+\frac{1}{4}+\frac{1}{4}}[/tex]
[tex]\\ \sf\longmapsto 2.91+2.91+2.91[/tex]
[tex]\\ \sf\longmapsto 3.73[/tex]