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Finding the Fourth Proportional to 389.92, 538.09 and 212.88

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Solution

The fourth proportional to 389.92, 538.09 and 212.88 is: 293.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.92 : 538.09 = 212.88 : x
  2. Step 2: Convert to fraction form
    389.92/538.09 = 212.88/x
  3. Step 3: Cross multiply
    389.92x = 538.09 × 212.88
  4. Step 4: Simplify right side
    389.92x = 114,547.29
  5. Step 5: Solve for x
    x = 114,547.29/389.92
  6. Step 6: Final answer
    x = 293.77

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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.