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Finding the Fourth Proportional to 645.90, 966.69 and 389.58

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Solution

The fourth proportional to 645.90, 966.69 and 389.58 is: 583.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.90 : 966.69 = 389.58 : x
  2. Step 2: Convert to fraction form
    645.90/966.69 = 389.58/x
  3. Step 3: Cross multiply
    645.90x = 966.69 × 389.58
  4. Step 4: Simplify right side
    645.90x = 376,603.09
  5. Step 5: Solve for x
    x = 376,603.09/645.90
  6. Step 6: Final answer
    x = 583.07

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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.