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Finding the Fourth Proportional to 388.31, 535.88 and 257.57

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Solution

The fourth proportional to 388.31, 535.88 and 257.57 is: 355.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.31 : 535.88 = 257.57 : x
  2. Step 2: Convert to fraction form
    388.31/535.88 = 257.57/x
  3. Step 3: Cross multiply
    388.31x = 535.88 × 257.57
  4. Step 4: Simplify right side
    388.31x = 138,024.58
  5. Step 5: Solve for x
    x = 138,024.58/388.31
  6. Step 6: Final answer
    x = 355.45

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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.