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Finding the Fourth Proportional to 668.81, 922.90 and 385.21

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Solution

The fourth proportional to 668.81, 922.90 and 385.21 is: 531.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.81 : 922.90 = 385.21 : x
  2. Step 2: Convert to fraction form
    668.81/922.90 = 385.21/x
  3. Step 3: Cross multiply
    668.81x = 922.90 × 385.21
  4. Step 4: Simplify right side
    668.81x = 355,510.14
  5. Step 5: Solve for x
    x = 355,510.14/668.81
  6. Step 6: Final answer
    x = 531.56

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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.