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Finding the Fourth Proportional to 389.91, 538.05 and 307.22

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Solution

The fourth proportional to 389.91, 538.05 and 307.22 is: 423.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.91 : 538.05 = 307.22 : x
  2. Step 2: Convert to fraction form
    389.91/538.05 = 307.22/x
  3. Step 3: Cross multiply
    389.91x = 538.05 × 307.22
  4. Step 4: Simplify right side
    389.91x = 165,299.72
  5. Step 5: Solve for x
    x = 165,299.72/389.91
  6. Step 6: Final answer
    x = 423.94

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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.