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Finding the Fourth Proportional to 1,399.60, 2,099.40 and 425.71

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Solution

The fourth proportional to 1,399.60, 2,099.40 and 425.71 is: 638.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,399.60 : 2,099.40 = 425.71 : x
  2. Step 2: Convert to fraction form
    1,399.60/2,099.40 = 425.71/x
  3. Step 3: Cross multiply
    1,399.60x = 2,099.40 × 425.71
  4. Step 4: Simplify right side
    1,399.60x = 893,735.57
  5. Step 5: Solve for x
    x = 893,735.57/1,399.60
  6. Step 6: Final answer
    x = 638.57

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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.