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Finding the Fourth Proportional to 693.88, 1,039.38 and 309.40

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Solution

The fourth proportional to 693.88, 1,039.38 and 309.40 is: 463.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    693.88 : 1,039.38 = 309.40 : x
  2. Step 2: Convert to fraction form
    693.88/1,039.38 = 309.40/x
  3. Step 3: Cross multiply
    693.88x = 1,039.38 × 309.40
  4. Step 4: Simplify right side
    693.88x = 321,584.17
  5. Step 5: Solve for x
    x = 321,584.17/693.88
  6. Step 6: Final answer
    x = 463.46

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.