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Finding the Fourth Proportional to 390.29, 538.31 and 361.13

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Solution

The fourth proportional to 390.29, 538.31 and 361.13 is: 498.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.29 : 538.31 = 361.13 : x
  2. Step 2: Convert to fraction form
    390.29/538.31 = 361.13/x
  3. Step 3: Cross multiply
    390.29x = 538.31 × 361.13
  4. Step 4: Simplify right side
    390.29x = 194,398.10
  5. Step 5: Solve for x
    x = 194,398.10/390.29
  6. Step 6: Final answer
    x = 498.09

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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.