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Finding the Fourth Proportional to 665.30, 918.09 and 385.35

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Solution

The fourth proportional to 665.30, 918.09 and 385.35 is: 531.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.30 : 918.09 = 385.35 : x
  2. Step 2: Convert to fraction form
    665.30/918.09 = 385.35/x
  3. Step 3: Cross multiply
    665.30x = 918.09 × 385.35
  4. Step 4: Simplify right side
    665.30x = 353,785.98
  5. Step 5: Solve for x
    x = 353,785.98/665.30
  6. Step 6: Final answer
    x = 531.77

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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.