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Finding the Fourth Proportional to 391.10, 539.98 and 317.57

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Solution

The fourth proportional to 391.10, 539.98 and 317.57 is: 438.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.10 : 539.98 = 317.57 : x
  2. Step 2: Convert to fraction form
    391.10/539.98 = 317.57/x
  3. Step 3: Cross multiply
    391.10x = 539.98 × 317.57
  4. Step 4: Simplify right side
    391.10x = 171,481.45
  5. Step 5: Solve for x
    x = 171,481.45/391.10
  6. Step 6: Final answer
    x = 438.46

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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.