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Finding the Fourth Proportional to 103.54, 142.88 and 56.91

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Solution

The fourth proportional to 103.54, 142.88 and 56.91 is: 78.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.54 : 142.88 = 56.91 : x
  2. Step 2: Convert to fraction form
    103.54/142.88 = 56.91/x
  3. Step 3: Cross multiply
    103.54x = 142.88 × 56.91
  4. Step 4: Simplify right side
    103.54x = 8,130.30
  5. Step 5: Solve for x
    x = 8,130.30/103.54
  6. Step 6: Final answer
    x = 78.53

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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.