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Finding the Fourth Proportional to 390.04, 538.20 and 215.36

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Solution

The fourth proportional to 390.04, 538.20 and 215.36 is: 297.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.04 : 538.20 = 215.36 : x
  2. Step 2: Convert to fraction form
    390.04/538.20 = 215.36/x
  3. Step 3: Cross multiply
    390.04x = 538.20 × 215.36
  4. Step 4: Simplify right side
    390.04x = 115,906.75
  5. Step 5: Solve for x
    x = 115,906.75/390.04
  6. Step 6: Final answer
    x = 297.17

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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.