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Finding the Fourth Proportional to 665.85, 918.83 and 400.31

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Solution

The fourth proportional to 665.85, 918.83 and 400.31 is: 552.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.85 : 918.83 = 400.31 : x
  2. Step 2: Convert to fraction form
    665.85/918.83 = 400.31/x
  3. Step 3: Cross multiply
    665.85x = 918.83 × 400.31
  4. Step 4: Simplify right side
    665.85x = 367,814.44
  5. Step 5: Solve for x
    x = 367,814.44/665.85
  6. Step 6: Final answer
    x = 552.40

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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.