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Finding the Fourth Proportional to 141.86, 212.86 and 69.78

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Solution

The fourth proportional to 141.86, 212.86 and 69.78 is: 104.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    141.86 : 212.86 = 69.78 : x
  2. Step 2: Convert to fraction form
    141.86/212.86 = 69.78/x
  3. Step 3: Cross multiply
    141.86x = 212.86 × 69.78
  4. Step 4: Simplify right side
    141.86x = 14,853.37
  5. Step 5: Solve for x
    x = 14,853.37/141.86
  6. Step 6: Final answer
    x = 104.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.