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Finding the Fourth Proportional to 103.45, 142.76 and 56.83

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Solution

The fourth proportional to 103.45, 142.76 and 56.83 is: 78.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.45 : 142.76 = 56.83 : x
  2. Step 2: Convert to fraction form
    103.45/142.76 = 56.83/x
  3. Step 3: Cross multiply
    103.45x = 142.76 × 56.83
  4. Step 4: Simplify right side
    103.45x = 8,113.05
  5. Step 5: Solve for x
    x = 8,113.05/103.45
  6. Step 6: Final answer
    x = 78.42

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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.