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Finding the Fourth Proportional to 807.28, 1,209.41 and 678.12

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Solution

The fourth proportional to 807.28, 1,209.41 and 678.12 is: 1,015.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.28 : 1,209.41 = 678.12 : x
  2. Step 2: Convert to fraction form
    807.28/1,209.41 = 678.12/x
  3. Step 3: Cross multiply
    807.28x = 1,209.41 × 678.12
  4. Step 4: Simplify right side
    807.28x = 820,119.06
  5. Step 5: Solve for x
    x = 820,119.06/807.28
  6. Step 6: Final answer
    x = 1,015.91

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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.