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Finding the Fourth Proportional to 80.30, 110.90 and 71.72

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Solution

The fourth proportional to 80.30, 110.90 and 71.72 is: 99.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.30 : 110.90 = 71.72 : x
  2. Step 2: Convert to fraction form
    80.30/110.90 = 71.72/x
  3. Step 3: Cross multiply
    80.30x = 110.90 × 71.72
  4. Step 4: Simplify right side
    80.30x = 7,953.19
  5. Step 5: Solve for x
    x = 7,953.19/80.30
  6. Step 6: Final answer
    x = 99.04

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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.