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Finding the Fourth Proportional to 309.12, 426.51 and 210.72

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Solution

The fourth proportional to 309.12, 426.51 and 210.72 is: 290.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.12 : 426.51 = 210.72 : x
  2. Step 2: Convert to fraction form
    309.12/426.51 = 210.72/x
  3. Step 3: Cross multiply
    309.12x = 426.51 × 210.72
  4. Step 4: Simplify right side
    309.12x = 89,874.19
  5. Step 5: Solve for x
    x = 89,874.19/309.12
  6. Step 6: Final answer
    x = 290.74

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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.