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Finding the Fourth Proportional to 659.91, 989.84 and 385.79

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Solution

The fourth proportional to 659.91, 989.84 and 385.79 is: 578.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.91 : 989.84 = 385.79 : x
  2. Step 2: Convert to fraction form
    659.91/989.84 = 385.79/x
  3. Step 3: Cross multiply
    659.91x = 989.84 × 385.79
  4. Step 4: Simplify right side
    659.91x = 381,873.81
  5. Step 5: Solve for x
    x = 381,873.81/659.91
  6. Step 6: Final answer
    x = 578.68

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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.