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Finding the Fourth Proportional to 55.72, 76.98 and 47.20

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Solution

The fourth proportional to 55.72, 76.98 and 47.20 is: 65.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.72 : 76.98 = 47.20 : x
  2. Step 2: Convert to fraction form
    55.72/76.98 = 47.20/x
  3. Step 3: Cross multiply
    55.72x = 76.98 × 47.20
  4. Step 4: Simplify right side
    55.72x = 3,633.46
  5. Step 5: Solve for x
    x = 3,633.46/55.72
  6. Step 6: Final answer
    x = 65.21

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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.