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Finding the Fourth Proportional to 770.78, 1,063.87 and 439.40

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Solution

The fourth proportional to 770.78, 1,063.87 and 439.40 is: 606.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.78 : 1,063.87 = 439.40 : x
  2. Step 2: Convert to fraction form
    770.78/1,063.87 = 439.40/x
  3. Step 3: Cross multiply
    770.78x = 1,063.87 × 439.40
  4. Step 4: Simplify right side
    770.78x = 467,458.06
  5. Step 5: Solve for x
    x = 467,458.06/770.78
  6. Step 6: Final answer
    x = 606.48

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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.