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Finding the Fourth Proportional to 390.29, 585.12 and 251.55

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Solution

The fourth proportional to 390.29, 585.12 and 251.55 is: 377.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.29 : 585.12 = 251.55 : x
  2. Step 2: Convert to fraction form
    390.29/585.12 = 251.55/x
  3. Step 3: Cross multiply
    390.29x = 585.12 × 251.55
  4. Step 4: Simplify right side
    390.29x = 147,186.94
  5. Step 5: Solve for x
    x = 147,186.94/390.29
  6. Step 6: Final answer
    x = 377.13

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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.