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Finding the Fourth Proportional to 611.85, 918.08 and 430.41

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Solution

The fourth proportional to 611.85, 918.08 and 430.41 is: 645.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.85 : 918.08 = 430.41 : x
  2. Step 2: Convert to fraction form
    611.85/918.08 = 430.41/x
  3. Step 3: Cross multiply
    611.85x = 918.08 × 430.41
  4. Step 4: Simplify right side
    611.85x = 395,156.14
  5. Step 5: Solve for x
    x = 395,156.14/611.85
  6. Step 6: Final answer
    x = 645.83

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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.