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Finding the Fourth Proportional to 611.79, 917.28 and 429.41

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Solution

The fourth proportional to 611.79, 917.28 and 429.41 is: 643.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.79 : 917.28 = 429.41 : x
  2. Step 2: Convert to fraction form
    611.79/917.28 = 429.41/x
  3. Step 3: Cross multiply
    611.79x = 917.28 × 429.41
  4. Step 4: Simplify right side
    611.79x = 393,884.62
  5. Step 5: Solve for x
    x = 393,884.62/611.79
  6. Step 6: Final answer
    x = 643.82

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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.