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Finding the Fourth Proportional to 71.88, 99.20 and 53.21

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Solution

The fourth proportional to 71.88, 99.20 and 53.21 is: 73.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.88 : 99.20 = 53.21 : x
  2. Step 2: Convert to fraction form
    71.88/99.20 = 53.21/x
  3. Step 3: Cross multiply
    71.88x = 99.20 × 53.21
  4. Step 4: Simplify right side
    71.88x = 5,278.43
  5. Step 5: Solve for x
    x = 5,278.43/71.88
  6. Step 6: Final answer
    x = 73.43

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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.