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Finding the Fourth Proportional to 387.77, 581.37 and 257.60

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Solution

The fourth proportional to 387.77, 581.37 and 257.60 is: 386.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.77 : 581.37 = 257.60 : x
  2. Step 2: Convert to fraction form
    387.77/581.37 = 257.60/x
  3. Step 3: Cross multiply
    387.77x = 581.37 × 257.60
  4. Step 4: Simplify right side
    387.77x = 149,761.40
  5. Step 5: Solve for x
    x = 149,761.40/387.77
  6. Step 6: Final answer
    x = 386.22

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.