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Finding the Fourth Proportional to 879.30, 1,318.95 and 809.10

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Solution

The fourth proportional to 879.30, 1,318.95 and 809.10 is: 1,213.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.30 : 1,318.95 = 809.10 : x
  2. Step 2: Convert to fraction form
    879.30/1,318.95 = 809.10/x
  3. Step 3: Cross multiply
    879.30x = 1,318.95 × 809.10
  4. Step 4: Simplify right side
    879.30x = 1,067,162.45
  5. Step 5: Solve for x
    x = 1,067,162.45/879.30
  6. Step 6: Final answer
    x = 1,213.65

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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.