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Finding the Fourth Proportional to 665.31, 918.20 and 403.48

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Solution

The fourth proportional to 665.31, 918.20 and 403.48 is: 556.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.31 : 918.20 = 403.48 : x
  2. Step 2: Convert to fraction form
    665.31/918.20 = 403.48/x
  3. Step 3: Cross multiply
    665.31x = 918.20 × 403.48
  4. Step 4: Simplify right side
    665.31x = 370,477.49
  5. Step 5: Solve for x
    x = 370,477.49/665.31
  6. Step 6: Final answer
    x = 556.85

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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.