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Finding the Fourth Proportional to 859.47, 1,289.20 and 210.21

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Solution

The fourth proportional to 859.47, 1,289.20 and 210.21 is: 315.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.47 : 1,289.20 = 210.21 : x
  2. Step 2: Convert to fraction form
    859.47/1,289.20 = 210.21/x
  3. Step 3: Cross multiply
    859.47x = 1,289.20 × 210.21
  4. Step 4: Simplify right side
    859.47x = 271,002.73
  5. Step 5: Solve for x
    x = 271,002.73/859.47
  6. Step 6: Final answer
    x = 315.31

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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.