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Finding the Fourth Proportional to 131.34, 181.32 and 78.90

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Solution

The fourth proportional to 131.34, 181.32 and 78.90 is: 108.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    131.34 : 181.32 = 78.90 : x
  2. Step 2: Convert to fraction form
    131.34/181.32 = 78.90/x
  3. Step 3: Cross multiply
    131.34x = 181.32 × 78.90
  4. Step 4: Simplify right side
    131.34x = 14,306.15
  5. Step 5: Solve for x
    x = 14,306.15/131.34
  6. Step 6: Final answer
    x = 108.92

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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.