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Finding the Fourth Proportional to 398.52, 552.51 and 390.60

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Solution

The fourth proportional to 398.52, 552.51 and 390.60 is: 541.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.52 : 552.51 = 390.60 : x
  2. Step 2: Convert to fraction form
    398.52/552.51 = 390.60/x
  3. Step 3: Cross multiply
    398.52x = 552.51 × 390.60
  4. Step 4: Simplify right side
    398.52x = 215,810.41
  5. Step 5: Solve for x
    x = 215,810.41/398.52
  6. Step 6: Final answer
    x = 541.53

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.