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Finding the Fourth Proportional to 402.34, 553.62 and 390.20

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Solution

The fourth proportional to 402.34, 553.62 and 390.20 is: 536.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    402.34 : 553.62 = 390.20 : x
  2. Step 2: Convert to fraction form
    402.34/553.62 = 390.20/x
  3. Step 3: Cross multiply
    402.34x = 553.62 × 390.20
  4. Step 4: Simplify right side
    402.34x = 216,022.52
  5. Step 5: Solve for x
    x = 216,022.52/402.34
  6. Step 6: Final answer
    x = 536.92

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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.