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Finding the Fourth Proportional to 398.72, 598.20 and 193.40

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Solution

The fourth proportional to 398.72, 598.20 and 193.40 is: 290.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.72 : 598.20 = 193.40 : x
  2. Step 2: Convert to fraction form
    398.72/598.20 = 193.40/x
  3. Step 3: Cross multiply
    398.72x = 598.20 × 193.40
  4. Step 4: Simplify right side
    398.72x = 115,691.88
  5. Step 5: Solve for x
    x = 115,691.88/398.72
  6. Step 6: Final answer
    x = 290.16

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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.