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Finding the Fourth Proportional to 42.30, 58.20 and 39.60

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Solution

The fourth proportional to 42.30, 58.20 and 39.60 is: 54.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.30 : 58.20 = 39.60 : x
  2. Step 2: Convert to fraction form
    42.30/58.20 = 39.60/x
  3. Step 3: Cross multiply
    42.30x = 58.20 × 39.60
  4. Step 4: Simplify right side
    42.30x = 2,304.72
  5. Step 5: Solve for x
    x = 2,304.72/42.30
  6. Step 6: Final answer
    x = 54.49

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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.