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Finding the Fourth Proportional to 859.71, 1,290.09 and 339.63

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Solution

The fourth proportional to 859.71, 1,290.09 and 339.63 is: 509.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.71 : 1,290.09 = 339.63 : x
  2. Step 2: Convert to fraction form
    859.71/1,290.09 = 339.63/x
  3. Step 3: Cross multiply
    859.71x = 1,290.09 × 339.63
  4. Step 4: Simplify right side
    859.71x = 438,149.70
  5. Step 5: Solve for x
    x = 438,149.70/859.71
  6. Step 6: Final answer
    x = 509.65

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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.