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Finding the Fourth Proportional to 789.68, 1,089.24 and 479.36

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Solution

The fourth proportional to 789.68, 1,089.24 and 479.36 is: 661.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.68 : 1,089.24 = 479.36 : x
  2. Step 2: Convert to fraction form
    789.68/1,089.24 = 479.36/x
  3. Step 3: Cross multiply
    789.68x = 1,089.24 × 479.36
  4. Step 4: Simplify right side
    789.68x = 522,138.09
  5. Step 5: Solve for x
    x = 522,138.09/789.68
  6. Step 6: Final answer
    x = 661.20

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.