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Finding the Fourth Proportional to 278.32, 417.55 and 139.58

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Solution

The fourth proportional to 278.32, 417.55 and 139.58 is: 209.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.32 : 417.55 = 139.58 : x
  2. Step 2: Convert to fraction form
    278.32/417.55 = 139.58/x
  3. Step 3: Cross multiply
    278.32x = 417.55 × 139.58
  4. Step 4: Simplify right side
    278.32x = 58,281.63
  5. Step 5: Solve for x
    x = 58,281.63/278.32
  6. Step 6: Final answer
    x = 209.41

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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.