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Finding the Fourth Proportional to 278.19, 417.31 and 72.77

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Solution

The fourth proportional to 278.19, 417.31 and 72.77 is: 109.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.19 : 417.31 = 72.77 : x
  2. Step 2: Convert to fraction form
    278.19/417.31 = 72.77/x
  3. Step 3: Cross multiply
    278.19x = 417.31 × 72.77
  4. Step 4: Simplify right side
    278.19x = 30,365.38
  5. Step 5: Solve for x
    x = 30,365.38/278.19
  6. Step 6: Final answer
    x = 109.15

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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.