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Finding the Fourth Proportional to 788.30, 1,087.90 and 439.02

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Solution

The fourth proportional to 788.30, 1,087.90 and 439.02 is: 605.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    788.30 : 1,087.90 = 439.02 : x
  2. Step 2: Convert to fraction form
    788.30/1,087.90 = 439.02/x
  3. Step 3: Cross multiply
    788.30x = 1,087.90 × 439.02
  4. Step 4: Simplify right side
    788.30x = 477,609.86
  5. Step 5: Solve for x
    x = 477,609.86/788.30
  6. Step 6: Final answer
    x = 605.87

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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.