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Finding the Fourth Proportional to 390.46, 538.10 and 279.75

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Solution

The fourth proportional to 390.46, 538.10 and 279.75 is: 385.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.46 : 538.10 = 279.75 : x
  2. Step 2: Convert to fraction form
    390.46/538.10 = 279.75/x
  3. Step 3: Cross multiply
    390.46x = 538.10 × 279.75
  4. Step 4: Simplify right side
    390.46x = 150,529.39
  5. Step 5: Solve for x
    x = 150,529.39/390.46
  6. Step 6: Final answer
    x = 385.52

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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.