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Finding the Fourth Proportional to 92.88, 139.40 and 72.81

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Solution

The fourth proportional to 92.88, 139.40 and 72.81 is: 109.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    92.88 : 139.40 = 72.81 : x
  2. Step 2: Convert to fraction form
    92.88/139.40 = 72.81/x
  3. Step 3: Cross multiply
    92.88x = 139.40 × 72.81
  4. Step 4: Simplify right side
    92.88x = 10,149.71
  5. Step 5: Solve for x
    x = 10,149.71/92.88
  6. Step 6: Final answer
    x = 109.28

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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.