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Finding the Fourth Proportional to 78.15, 116.66 and 77.97

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Solution

The fourth proportional to 78.15, 116.66 and 77.97 is: 116.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.15 : 116.66 = 77.97 : x
  2. Step 2: Convert to fraction form
    78.15/116.66 = 77.97/x
  3. Step 3: Cross multiply
    78.15x = 116.66 × 77.97
  4. Step 4: Simplify right side
    78.15x = 9,095.59
  5. Step 5: Solve for x
    x = 9,095.59/78.15
  6. Step 6: Final answer
    x = 116.39

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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.