Answer:
The maximum value of the magnetic field in the wave is  .
.
Explanation:
Given that,
Average value of pointing vector = 0.724 W/m²
We need to calculate the magnetic field
Using formula of pointing vector

The average value of pointing vector
 ....(I)
....(I)
We know that,

Put the value of  in equation (II)
 in equation (II)

Put the value into the formula



Hence, The maximum value of the magnetic field in the wave is  .
.