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Finding the Fourth Proportional to 80.63, 111.03 and 71.42

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Solution

The fourth proportional to 80.63, 111.03 and 71.42 is: 98.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.63 : 111.03 = 71.42 : x
  2. Step 2: Convert to fraction form
    80.63/111.03 = 71.42/x
  3. Step 3: Cross multiply
    80.63x = 111.03 × 71.42
  4. Step 4: Simplify right side
    80.63x = 7,929.76
  5. Step 5: Solve for x
    x = 7,929.76/80.63
  6. Step 6: Final answer
    x = 98.35

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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.