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Finding the Fourth Proportional to 800.40, 1,200.60 and 789.60

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Solution

The fourth proportional to 800.40, 1,200.60 and 789.60 is: 1,184.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    800.40 : 1,200.60 = 789.60 : x
  2. Step 2: Convert to fraction form
    800.40/1,200.60 = 789.60/x
  3. Step 3: Cross multiply
    800.40x = 1,200.60 × 789.60
  4. Step 4: Simplify right side
    800.40x = 947,993.76
  5. Step 5: Solve for x
    x = 947,993.76/800.40
  6. Step 6: Final answer
    x = 1,184.40

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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.