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Finding the Fourth Proportional to 789.80, 1,089.88 and 440.42

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Solution

The fourth proportional to 789.80, 1,089.88 and 440.42 is: 607.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    789.80 : 1,089.88 = 440.42 : x
  2. Step 2: Convert to fraction form
    789.80/1,089.88 = 440.42/x
  3. Step 3: Cross multiply
    789.80x = 1,089.88 × 440.42
  4. Step 4: Simplify right side
    789.80x = 479,998.40
  5. Step 5: Solve for x
    x = 479,998.40/789.80
  6. Step 6: Final answer
    x = 607.75

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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.