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Finding the Fourth Proportional to 438.60, 605.63 and 391.89

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Solution

The fourth proportional to 438.60, 605.63 and 391.89 is: 541.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.60 : 605.63 = 391.89 : x
  2. Step 2: Convert to fraction form
    438.60/605.63 = 391.89/x
  3. Step 3: Cross multiply
    438.60x = 605.63 × 391.89
  4. Step 4: Simplify right side
    438.60x = 237,340.34
  5. Step 5: Solve for x
    x = 237,340.34/438.60
  6. Step 6: Final answer
    x = 541.13

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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.