Answer: The required percentage would be 5.4%.
Step-by-step explanation:
Since we have given that
Worth of Company A = $4150
Worth of Company B = $6820
So, increase in Company A = 6%
increase in Company B = 5%
According to question, it becomes,
[tex]0.06\times 4150+0.05\times 6820\\\\=249+341\\\\=590[/tex]
So, the total percentage increase in the investor's stock account would be
[tex]\dfrac{590}{4150+6820}\times 100\\\\=\dfrac{590}{10970}\times 100\\\\=5.378\%[/tex]
Hence, the required percentage would be 5.4%.