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Finding the Fourth Proportional to 278.59, 417.89 and 86.22

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Solution

The fourth proportional to 278.59, 417.89 and 86.22 is: 129.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.59 : 417.89 = 86.22 : x
  2. Step 2: Convert to fraction form
    278.59/417.89 = 86.22/x
  3. Step 3: Cross multiply
    278.59x = 417.89 × 86.22
  4. Step 4: Simplify right side
    278.59x = 36,030.48
  5. Step 5: Solve for x
    x = 36,030.48/278.59
  6. Step 6: Final answer
    x = 129.33

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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.