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Finding the Fourth Proportional to 354.90, 489.85 and 317.99

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Solution

The fourth proportional to 354.90, 489.85 and 317.99 is: 438.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    354.90 : 489.85 = 317.99 : x
  2. Step 2: Convert to fraction form
    354.90/489.85 = 317.99/x
  3. Step 3: Cross multiply
    354.90x = 489.85 × 317.99
  4. Step 4: Simplify right side
    354.90x = 155,770.54
  5. Step 5: Solve for x
    x = 155,770.54/354.90
  6. Step 6: Final answer
    x = 438.91

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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.