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Finding the Fourth Proportional to 403.30, 556.03 and 390.54

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Solution

The fourth proportional to 403.30, 556.03 and 390.54 is: 538.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.30 : 556.03 = 390.54 : x
  2. Step 2: Convert to fraction form
    403.30/556.03 = 390.54/x
  3. Step 3: Cross multiply
    403.30x = 556.03 × 390.54
  4. Step 4: Simplify right side
    403.30x = 217,154.53
  5. Step 5: Solve for x
    x = 217,154.53/403.30
  6. Step 6: Final answer
    x = 538.44

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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.