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Finding the Fourth Proportional to 392.90, 541.31 and 309.98

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Solution

The fourth proportional to 392.90, 541.31 and 309.98 is: 427.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.90 : 541.31 = 309.98 : x
  2. Step 2: Convert to fraction form
    392.90/541.31 = 309.98/x
  3. Step 3: Cross multiply
    392.90x = 541.31 × 309.98
  4. Step 4: Simplify right side
    392.90x = 167,792.90
  5. Step 5: Solve for x
    x = 167,792.90/392.90
  6. Step 6: Final answer
    x = 427.06

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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.