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Finding the Fourth Proportional to 393.12, 539.28 and 380.16

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Solution

The fourth proportional to 393.12, 539.28 and 380.16 is: 521.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.12 : 539.28 = 380.16 : x
  2. Step 2: Convert to fraction form
    393.12/539.28 = 380.16/x
  3. Step 3: Cross multiply
    393.12x = 539.28 × 380.16
  4. Step 4: Simplify right side
    393.12x = 205,012.68
  5. Step 5: Solve for x
    x = 205,012.68/393.12
  6. Step 6: Final answer
    x = 521.50

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.