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Finding the Fourth Proportional to 103.48, 142.79 and 56.85

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Solution

The fourth proportional to 103.48, 142.79 and 56.85 is: 78.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.48 : 142.79 = 56.85 : x
  2. Step 2: Convert to fraction form
    103.48/142.79 = 56.85/x
  3. Step 3: Cross multiply
    103.48x = 142.79 × 56.85
  4. Step 4: Simplify right side
    103.48x = 8,117.27
  5. Step 5: Solve for x
    x = 8,117.27/103.48
  6. Step 6: Final answer
    x = 78.45

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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.