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Finding the Fourth Proportional to 665.15, 917.73 and 385.43

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Solution

The fourth proportional to 665.15, 917.73 and 385.43 is: 531.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.15 : 917.73 = 385.43 : x
  2. Step 2: Convert to fraction form
    665.15/917.73 = 385.43/x
  3. Step 3: Cross multiply
    665.15x = 917.73 × 385.43
  4. Step 4: Simplify right side
    665.15x = 353,716.09
  5. Step 5: Solve for x
    x = 353,716.09/665.15
  6. Step 6: Final answer
    x = 531.79

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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.