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Finding the Fourth Proportional to 438.58, 605.70 and 392.80

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Solution

The fourth proportional to 438.58, 605.70 and 392.80 is: 542.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.58 : 605.70 = 392.80 : x
  2. Step 2: Convert to fraction form
    438.58/605.70 = 392.80/x
  3. Step 3: Cross multiply
    438.58x = 605.70 × 392.80
  4. Step 4: Simplify right side
    438.58x = 237,918.96
  5. Step 5: Solve for x
    x = 237,918.96/438.58
  6. Step 6: Final answer
    x = 542.48

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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.