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Finding the Fourth Proportional to 388.68, 535.86 and 257.64

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Solution

The fourth proportional to 388.68, 535.86 and 257.64 is: 355.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.68 : 535.86 = 257.64 : x
  2. Step 2: Convert to fraction form
    388.68/535.86 = 257.64/x
  3. Step 3: Cross multiply
    388.68x = 535.86 × 257.64
  4. Step 4: Simplify right side
    388.68x = 138,058.97
  5. Step 5: Solve for x
    x = 138,058.97/388.68
  6. Step 6: Final answer
    x = 355.20

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.