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Finding the Fourth Proportional to 102.08, 140.93 and 78.72

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Solution

The fourth proportional to 102.08, 140.93 and 78.72 is: 108.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.08 : 140.93 = 78.72 : x
  2. Step 2: Convert to fraction form
    102.08/140.93 = 78.72/x
  3. Step 3: Cross multiply
    102.08x = 140.93 × 78.72
  4. Step 4: Simplify right side
    102.08x = 11,094.21
  5. Step 5: Solve for x
    x = 11,094.21/102.08
  6. Step 6: Final answer
    x = 108.68

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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.