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Finding the Fourth Proportional to 438.95, 605.78 and 389.75

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Solution

The fourth proportional to 438.95, 605.78 and 389.75 is: 537.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.95 : 605.78 = 389.75 : x
  2. Step 2: Convert to fraction form
    438.95/605.78 = 389.75/x
  3. Step 3: Cross multiply
    438.95x = 605.78 × 389.75
  4. Step 4: Simplify right side
    438.95x = 236,099.24
  5. Step 5: Solve for x
    x = 236,099.24/438.95
  6. Step 6: Final answer
    x = 537.87

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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.