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Finding the Fourth Proportional to 79.88, 119.96 and 71.40

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Solution

The fourth proportional to 79.88, 119.96 and 71.40 is: 107.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.88 : 119.96 = 71.40 : x
  2. Step 2: Convert to fraction form
    79.88/119.96 = 71.40/x
  3. Step 3: Cross multiply
    79.88x = 119.96 × 71.40
  4. Step 4: Simplify right side
    79.88x = 8,565.14
  5. Step 5: Solve for x
    x = 8,565.14/79.88
  6. Step 6: Final answer
    x = 107.23

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.