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Finding the Fourth Proportional to 83.40, 114.90 and 71.70

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Solution

The fourth proportional to 83.40, 114.90 and 71.70 is: 98.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.40 : 114.90 = 71.70 : x
  2. Step 2: Convert to fraction form
    83.40/114.90 = 71.70/x
  3. Step 3: Cross multiply
    83.40x = 114.90 × 71.70
  4. Step 4: Simplify right side
    83.40x = 8,238.33
  5. Step 5: Solve for x
    x = 8,238.33/83.40
  6. Step 6: Final answer
    x = 98.78

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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.