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Finding the Fourth Proportional to 611.91, 917.64 and 429.39

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Solution

The fourth proportional to 611.91, 917.64 and 429.39 is: 643.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.91 : 917.64 = 429.39 : x
  2. Step 2: Convert to fraction form
    611.91/917.64 = 429.39/x
  3. Step 3: Cross multiply
    611.91x = 917.64 × 429.39
  4. Step 4: Simplify right side
    611.91x = 394,025.44
  5. Step 5: Solve for x
    x = 394,025.44/611.91
  6. Step 6: Final answer
    x = 643.93

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.