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Finding the Fourth Proportional to 54.30, 74.88 and 39.72

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Solution

The fourth proportional to 54.30, 74.88 and 39.72 is: 54.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.30 : 74.88 = 39.72 : x
  2. Step 2: Convert to fraction form
    54.30/74.88 = 39.72/x
  3. Step 3: Cross multiply
    54.30x = 74.88 × 39.72
  4. Step 4: Simplify right side
    54.30x = 2,974.23
  5. Step 5: Solve for x
    x = 2,974.23/54.30
  6. Step 6: Final answer
    x = 54.77

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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.