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Finding the Fourth Proportional to 807.60, 1,209.60 and 699.60

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Solution

The fourth proportional to 807.60, 1,209.60 and 699.60 is: 1,047.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.60 : 1,209.60 = 699.60 : x
  2. Step 2: Convert to fraction form
    807.60/1,209.60 = 699.60/x
  3. Step 3: Cross multiply
    807.60x = 1,209.60 × 699.60
  4. Step 4: Simplify right side
    807.60x = 846,236.16
  5. Step 5: Solve for x
    x = 846,236.16/807.60
  6. Step 6: Final answer
    x = 1,047.84

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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.