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Finding the Fourth Proportional to 561.21, 839.76 and 330.20

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Solution

The fourth proportional to 561.21, 839.76 and 330.20 is: 494.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.21 : 839.76 = 330.20 : x
  2. Step 2: Convert to fraction form
    561.21/839.76 = 330.20/x
  3. Step 3: Cross multiply
    561.21x = 839.76 × 330.20
  4. Step 4: Simplify right side
    561.21x = 277,289.61
  5. Step 5: Solve for x
    x = 277,289.61/561.21
  6. Step 6: Final answer
    x = 494.10

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.