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Finding the Fourth Proportional to 72.30, 99.77 and 39.55

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Solution

The fourth proportional to 72.30, 99.77 and 39.55 is: 54.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.30 : 99.77 = 39.55 : x
  2. Step 2: Convert to fraction form
    72.30/99.77 = 39.55/x
  3. Step 3: Cross multiply
    72.30x = 99.77 × 39.55
  4. Step 4: Simplify right side
    72.30x = 3,945.56
  5. Step 5: Solve for x
    x = 3,945.56/72.30
  6. Step 6: Final answer
    x = 54.58

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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.