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Finding the Fourth Proportional to 789, 1,089.14 and 513.80

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Solution

The fourth proportional to 789, 1,089.14 and 513.80 is: 709.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    789 : 1,089.14 = 513.80 : x
  2. Step 2: Convert to fraction form
    789/1,089.14 = 513.80/x
  3. Step 3: Cross multiply
    789x = 1,089.14 × 513.80
  4. Step 4: Simplify right side
    789x = 559,600.13
  5. Step 5: Solve for x
    x = 559,600.13/789
  6. Step 6: Final answer
    x = 709.25

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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.