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Finding the Fourth Proportional to 210.13, 315.20 and 65.85

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Solution

The fourth proportional to 210.13, 315.20 and 65.85 is: 98.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    210.13 : 315.20 = 65.85 : x
  2. Step 2: Convert to fraction form
    210.13/315.20 = 65.85/x
  3. Step 3: Cross multiply
    210.13x = 315.20 × 65.85
  4. Step 4: Simplify right side
    210.13x = 20,755.92
  5. Step 5: Solve for x
    x = 20,755.92/210.13
  6. Step 6: Final answer
    x = 98.78

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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.