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Finding the Fourth Proportional to 71.55, 98.74 and 38.80

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Solution

The fourth proportional to 71.55, 98.74 and 38.80 is: 53.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.55 : 98.74 = 38.80 : x
  2. Step 2: Convert to fraction form
    71.55/98.74 = 38.80/x
  3. Step 3: Cross multiply
    71.55x = 98.74 × 38.80
  4. Step 4: Simplify right side
    71.55x = 3,830.86
  5. Step 5: Solve for x
    x = 3,830.86/71.55
  6. Step 6: Final answer
    x = 53.54

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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.