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Finding the Fourth Proportional to 668.98, 923.20 and 389.21

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Solution

The fourth proportional to 668.98, 923.20 and 389.21 is: 537.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.98 : 923.20 = 389.21 : x
  2. Step 2: Convert to fraction form
    668.98/923.20 = 389.21/x
  3. Step 3: Cross multiply
    668.98x = 923.20 × 389.21
  4. Step 4: Simplify right side
    668.98x = 359,320.01
  5. Step 5: Solve for x
    x = 359,320.01/668.98
  6. Step 6: Final answer
    x = 537.12

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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.