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Finding the Fourth Proportional to 873.60, 1,305.60 and 787.20

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Solution

The fourth proportional to 873.60, 1,305.60 and 787.20 is: 1,176.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    873.60 : 1,305.60 = 787.20 : x
  2. Step 2: Convert to fraction form
    873.60/1,305.60 = 787.20/x
  3. Step 3: Cross multiply
    873.60x = 1,305.60 × 787.20
  4. Step 4: Simplify right side
    873.60x = 1,027,768.32
  5. Step 5: Solve for x
    x = 1,027,768.32/873.60
  6. Step 6: Final answer
    x = 1,176.47

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.