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Finding the Fourth Proportional to 859.31, 1,289.70 and 339.68

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Solution

The fourth proportional to 859.31, 1,289.70 and 339.68 is: 509.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.31 : 1,289.70 = 339.68 : x
  2. Step 2: Convert to fraction form
    859.31/1,289.70 = 339.68/x
  3. Step 3: Cross multiply
    859.31x = 1,289.70 × 339.68
  4. Step 4: Simplify right side
    859.31x = 438,085.30
  5. Step 5: Solve for x
    x = 438,085.30/859.31
  6. Step 6: Final answer
    x = 509.81

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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.