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Finding the Fourth Proportional to 1,205.78, 1,808.21 and 425.63

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Solution

The fourth proportional to 1,205.78, 1,808.21 and 425.63 is: 638.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,205.78 : 1,808.21 = 425.63 : x
  2. Step 2: Convert to fraction form
    1,205.78/1,808.21 = 425.63/x
  3. Step 3: Cross multiply
    1,205.78x = 1,808.21 × 425.63
  4. Step 4: Simplify right side
    1,205.78x = 769,630.81
  5. Step 5: Solve for x
    x = 769,630.81/1,205.78
  6. Step 6: Final answer
    x = 638.29

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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.