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Finding the Fourth Proportional to 389.84, 537.20 and 307.28

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Solution

The fourth proportional to 389.84, 537.20 and 307.28 is: 423.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.84 : 537.20 = 307.28 : x
  2. Step 2: Convert to fraction form
    389.84/537.20 = 307.28/x
  3. Step 3: Cross multiply
    389.84x = 537.20 × 307.28
  4. Step 4: Simplify right side
    389.84x = 165,070.82
  5. Step 5: Solve for x
    x = 165,070.82/389.84
  6. Step 6: Final answer
    x = 423.43

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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.