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Finding the Fourth Proportional to 390.21, 538.46 and 224.40

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Solution

The fourth proportional to 390.21, 538.46 and 224.40 is: 309.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.21 : 538.46 = 224.40 : x
  2. Step 2: Convert to fraction form
    390.21/538.46 = 224.40/x
  3. Step 3: Cross multiply
    390.21x = 538.46 × 224.40
  4. Step 4: Simplify right side
    390.21x = 120,826.61
  5. Step 5: Solve for x
    x = 120,826.61/390.21
  6. Step 6: Final answer
    x = 309.65

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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.