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Finding the Fourth Proportional to 398.40, 596.69 and 391.72

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Solution

The fourth proportional to 398.40, 596.69 and 391.72 is: 586.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.40 : 596.69 = 391.72 : x
  2. Step 2: Convert to fraction form
    398.40/596.69 = 391.72/x
  3. Step 3: Cross multiply
    398.40x = 596.69 × 391.72
  4. Step 4: Simplify right side
    398.40x = 233,735.65
  5. Step 5: Solve for x
    x = 233,735.65/398.40
  6. Step 6: Final answer
    x = 586.68

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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.