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Finding the Fourth Proportional to 103.47, 142.76 and 77.55

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Solution

The fourth proportional to 103.47, 142.76 and 77.55 is: 106.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.47 : 142.76 = 77.55 : x
  2. Step 2: Convert to fraction form
    103.47/142.76 = 77.55/x
  3. Step 3: Cross multiply
    103.47x = 142.76 × 77.55
  4. Step 4: Simplify right side
    103.47x = 11,070.65
  5. Step 5: Solve for x
    x = 11,070.65/103.47
  6. Step 6: Final answer
    x = 106.99

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.