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Finding the Fourth Proportional to 393.89, 543.63 and 280.51

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Solution

The fourth proportional to 393.89, 543.63 and 280.51 is: 387.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.89 : 543.63 = 280.51 : x
  2. Step 2: Convert to fraction form
    393.89/543.63 = 280.51/x
  3. Step 3: Cross multiply
    393.89x = 543.63 × 280.51
  4. Step 4: Simplify right side
    393.89x = 152,490.93
  5. Step 5: Solve for x
    x = 152,490.93/393.89
  6. Step 6: Final answer
    x = 387.14

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.