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Finding the Fourth Proportional to 859.79, 1,288.81 and 339.69

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Solution

The fourth proportional to 859.79, 1,288.81 and 339.69 is: 509.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.79 : 1,288.81 = 339.69 : x
  2. Step 2: Convert to fraction form
    859.79/1,288.81 = 339.69/x
  3. Step 3: Cross multiply
    859.79x = 1,288.81 × 339.69
  4. Step 4: Simplify right side
    859.79x = 437,801.13
  5. Step 5: Solve for x
    x = 437,801.13/859.79
  6. Step 6: Final answer
    x = 509.20

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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.