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Finding the Fourth Proportional to 83.25, 124.13 and 78.66

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Solution

The fourth proportional to 83.25, 124.13 and 78.66 is: 117.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.25 : 124.13 = 78.66 : x
  2. Step 2: Convert to fraction form
    83.25/124.13 = 78.66/x
  3. Step 3: Cross multiply
    83.25x = 124.13 × 78.66
  4. Step 4: Simplify right side
    83.25x = 9,763.67
  5. Step 5: Solve for x
    x = 9,763.67/83.25
  6. Step 6: Final answer
    x = 117.28

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.