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Finding the Fourth Proportional to 399.18, 598.78 and 142.68

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Solution

The fourth proportional to 399.18, 598.78 and 142.68 is: 214.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.18 : 598.78 = 142.68 : x
  2. Step 2: Convert to fraction form
    399.18/598.78 = 142.68/x
  3. Step 3: Cross multiply
    399.18x = 598.78 × 142.68
  4. Step 4: Simplify right side
    399.18x = 85,433.93
  5. Step 5: Solve for x
    x = 85,433.93/399.18
  6. Step 6: Final answer
    x = 214.02

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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.