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Finding the Fourth Proportional to 666.34, 918.57 and 469.78

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Solution

The fourth proportional to 666.34, 918.57 and 469.78 is: 647.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.34 : 918.57 = 469.78 : x
  2. Step 2: Convert to fraction form
    666.34/918.57 = 469.78/x
  3. Step 3: Cross multiply
    666.34x = 918.57 × 469.78
  4. Step 4: Simplify right side
    666.34x = 431,525.81
  5. Step 5: Solve for x
    x = 431,525.81/666.34
  6. Step 6: Final answer
    x = 647.61

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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.