factory manufactured a kind of parts last year, and the cost gradually decreased. The cost in each quarter was 25% lower than the previous quarter. The cost in the first quarter was 64 yuan. Q: How much is the cost in the fourth quarter?
某工厂去年制造一种零件，成本逐渐下降，每一季度成本比前一季度降低25%，第一季度的成本是64元，问：第四季度的成本是多少元？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">64 * (3/4) * (3/4) * (3/4)</gadget>
<output>27</output>

<result>27</result>