Answer
The molar mass for $C_{21}H_{26}O_5$ is equal to 358.42 g/mole
Work Step by Step
Molar Mass ($C_{21}H_{26}O_5$):
$C: 12.01g * 21= 252.21g $
$H: 1.008g * 26= 26.208g $
$O: 16.00g * 5= 80.00g $
252.21g + 26.208g + 80.00g = 358.42g