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Finding the Fourth Proportional to 859.65, 1,288.90 and 396.80

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Solution

The fourth proportional to 859.65, 1,288.90 and 396.80 is: 594.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    859.65 : 1,288.90 = 396.80 : x
  2. Step 2: Convert to fraction form
    859.65/1,288.90 = 396.80/x
  3. Step 3: Cross multiply
    859.65x = 1,288.90 × 396.80
  4. Step 4: Simplify right side
    859.65x = 511,439.24
  5. Step 5: Solve for x
    x = 511,439.24/859.65
  6. Step 6: Final answer
    x = 594.94

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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.