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Finding the Fourth Proportional to 647.21, 971.27 and 387.05

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Solution

The fourth proportional to 647.21, 971.27 and 387.05 is: 580.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    647.21 : 971.27 = 387.05 : x
  2. Step 2: Convert to fraction form
    647.21/971.27 = 387.05/x
  3. Step 3: Cross multiply
    647.21x = 971.27 × 387.05
  4. Step 4: Simplify right side
    647.21x = 375,930.05
  5. Step 5: Solve for x
    x = 375,930.05/647.21
  6. Step 6: Final answer
    x = 580.85

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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.