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Finding the Fourth Proportional to 140.40, 210.60 and 68.28

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Solution

The fourth proportional to 140.40, 210.60 and 68.28 is: 102.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.40 : 210.60 = 68.28 : x
  2. Step 2: Convert to fraction form
    140.40/210.60 = 68.28/x
  3. Step 3: Cross multiply
    140.40x = 210.60 × 68.28
  4. Step 4: Simplify right side
    140.40x = 14,379.77
  5. Step 5: Solve for x
    x = 14,379.77/140.40
  6. Step 6: Final answer
    x = 102.42

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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.