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Finding the Fourth Proportional to 398.42, 597.86 and 215.81

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Solution

The fourth proportional to 398.42, 597.86 and 215.81 is: 323.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.42 : 597.86 = 215.81 : x
  2. Step 2: Convert to fraction form
    398.42/597.86 = 215.81/x
  3. Step 3: Cross multiply
    398.42x = 597.86 × 215.81
  4. Step 4: Simplify right side
    398.42x = 129,024.17
  5. Step 5: Solve for x
    x = 129,024.17/398.42
  6. Step 6: Final answer
    x = 323.84

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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.