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Finding the Fourth Proportional to 140.42, 210.72 and 79.68

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Solution

The fourth proportional to 140.42, 210.72 and 79.68 is: 119.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.42 : 210.72 = 79.68 : x
  2. Step 2: Convert to fraction form
    140.42/210.72 = 79.68/x
  3. Step 3: Cross multiply
    140.42x = 210.72 × 79.68
  4. Step 4: Simplify right side
    140.42x = 16,790.17
  5. Step 5: Solve for x
    x = 16,790.17/140.42
  6. Step 6: Final answer
    x = 119.57

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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.