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Finding the Fourth Proportional to 390.30, 538.30 and 343.57

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Solution

The fourth proportional to 390.30, 538.30 and 343.57 is: 473.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.30 : 538.30 = 343.57 : x
  2. Step 2: Convert to fraction form
    390.30/538.30 = 343.57/x
  3. Step 3: Cross multiply
    390.30x = 538.30 × 343.57
  4. Step 4: Simplify right side
    390.30x = 184,943.73
  5. Step 5: Solve for x
    x = 184,943.73/390.30
  6. Step 6: Final answer
    x = 473.85

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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.