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Finding the Fourth Proportional to 54.78, 82.08 and 42.72

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Solution

The fourth proportional to 54.78, 82.08 and 42.72 is: 64.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    54.78 : 82.08 = 42.72 : x
  2. Step 2: Convert to fraction form
    54.78/82.08 = 42.72/x
  3. Step 3: Cross multiply
    54.78x = 82.08 × 42.72
  4. Step 4: Simplify right side
    54.78x = 3,506.46
  5. Step 5: Solve for x
    x = 3,506.46/54.78
  6. Step 6: Final answer
    x = 64.01

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.