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Finding the Fourth Proportional to 256.78, 354.02 and 209.58

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Solution

The fourth proportional to 256.78, 354.02 and 209.58 is: 288.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.78 : 354.02 = 209.58 : x
  2. Step 2: Convert to fraction form
    256.78/354.02 = 209.58/x
  3. Step 3: Cross multiply
    256.78x = 354.02 × 209.58
  4. Step 4: Simplify right side
    256.78x = 74,195.51
  5. Step 5: Solve for x
    x = 74,195.51/256.78
  6. Step 6: Final answer
    x = 288.95

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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.