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Finding the Fourth Proportional to 1,213.50, 1,820.30 and 391.71

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Solution

The fourth proportional to 1,213.50, 1,820.30 and 391.71 is: 587.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,213.50 : 1,820.30 = 391.71 : x
  2. Step 2: Convert to fraction form
    1,213.50/1,820.30 = 391.71/x
  3. Step 3: Cross multiply
    1,213.50x = 1,820.30 × 391.71
  4. Step 4: Simplify right side
    1,213.50x = 713,027.75
  5. Step 5: Solve for x
    x = 713,027.75/1,213.50
  6. Step 6: Final answer
    x = 587.58

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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.