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Finding the Fourth Proportional to 770.90, 1,063.80 and 439.40

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Solution

The fourth proportional to 770.90, 1,063.80 and 439.40 is: 606.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    770.90 : 1,063.80 = 439.40 : x
  2. Step 2: Convert to fraction form
    770.90/1,063.80 = 439.40/x
  3. Step 3: Cross multiply
    770.90x = 1,063.80 × 439.40
  4. Step 4: Simplify right side
    770.90x = 467,436.38
  5. Step 5: Solve for x
    x = 467,436.38/770.90
  6. Step 6: Final answer
    x = 606.36

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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.