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Finding the Fourth Proportional to 403.78, 557.28 and 256.48

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Solution

The fourth proportional to 403.78, 557.28 and 256.48 is: 353.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.78 : 557.28 = 256.48 : x
  2. Step 2: Convert to fraction form
    403.78/557.28 = 256.48/x
  3. Step 3: Cross multiply
    403.78x = 557.28 × 256.48
  4. Step 4: Simplify right side
    403.78x = 142,931.17
  5. Step 5: Solve for x
    x = 142,931.17/403.78
  6. Step 6: Final answer
    x = 353.98

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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.