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Finding the Fourth Proportional to 390.39, 538.19 and 279.83

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Solution

The fourth proportional to 390.39, 538.19 and 279.83 is: 385.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.39 : 538.19 = 279.83 : x
  2. Step 2: Convert to fraction form
    390.39/538.19 = 279.83/x
  3. Step 3: Cross multiply
    390.39x = 538.19 × 279.83
  4. Step 4: Simplify right side
    390.39x = 150,597.62
  5. Step 5: Solve for x
    x = 150,597.62/390.39
  6. Step 6: Final answer
    x = 385.76

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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.