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Finding the Fourth Proportional to 665.43, 918.80 and 403.80

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Solution

The fourth proportional to 665.43, 918.80 and 403.80 is: 557.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.43 : 918.80 = 403.80 : x
  2. Step 2: Convert to fraction form
    665.43/918.80 = 403.80/x
  3. Step 3: Cross multiply
    665.43x = 918.80 × 403.80
  4. Step 4: Simplify right side
    665.43x = 371,009.42
  5. Step 5: Solve for x
    x = 371,009.42/665.43
  6. Step 6: Final answer
    x = 557.55

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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.