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Finding the Fourth Proportional to 278.03, 417.12 and 85.66

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Solution

The fourth proportional to 278.03, 417.12 and 85.66 is: 128.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.03 : 417.12 = 85.66 : x
  2. Step 2: Convert to fraction form
    278.03/417.12 = 85.66/x
  3. Step 3: Cross multiply
    278.03x = 417.12 × 85.66
  4. Step 4: Simplify right side
    278.03x = 35,730.50
  5. Step 5: Solve for x
    x = 35,730.50/278.03
  6. Step 6: Final answer
    x = 128.51

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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.