Help with Interest Question

[DesignatedT]

Use the commission schedule shown in the table to find the annual rate of interest earned on the investment.

Principal(Value of Stock)---Commission
Under $3,000---$25+1.8% of principal
$3,000 to $10,000---$37+1.4% of principal
Over $10,000---$107 +0.7% of principal

An Investor purchases 300 shares at $11.14 a share, holds the stock for 51 weeks, and then sells the stock for $18.04 a share

The annual rate is ????% (Round to 5 decimal places)
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I know the A=P+Prt=P(1+rt) but I'm having problems with this. Thanks to anyone who's willing to help.

 

[tkhunny]

You will have to calculate the principal. What is it?

 

[DesignatedT]

I believe the principal would just be the 300 shares at $11.14/share. Making it $3,342.

 

[DesignatedT]

That could be right Denis but it says round to 5 decimal places.

 

[HallsofIvy]

I should have read the other posts first!