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Finding the Fourth Proportional to 390.43, 585.28 and 133.75

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Solution

The fourth proportional to 390.43, 585.28 and 133.75 is: 200.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.43 : 585.28 = 133.75 : x
  2. Step 2: Convert to fraction form
    390.43/585.28 = 133.75/x
  3. Step 3: Cross multiply
    390.43x = 585.28 × 133.75
  4. Step 4: Simplify right side
    390.43x = 78,281.20
  5. Step 5: Solve for x
    x = 78,281.20/390.43
  6. Step 6: Final answer
    x = 200.50

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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.