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Finding the Fourth Proportional to 278.47, 417.71 and 86.10

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Solution

The fourth proportional to 278.47, 417.71 and 86.10 is: 129.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.47 : 417.71 = 86.10 : x
  2. Step 2: Convert to fraction form
    278.47/417.71 = 86.10/x
  3. Step 3: Cross multiply
    278.47x = 417.71 × 86.10
  4. Step 4: Simplify right side
    278.47x = 35,962.74
  5. Step 5: Solve for x
    x = 35,962.74/278.47
  6. Step 6: Final answer
    x = 129.14

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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.