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Finding the Fourth Proportional to 78.45, 117.78 and 61.44

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Solution

The fourth proportional to 78.45, 117.78 and 61.44 is: 92.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.45 : 117.78 = 61.44 : x
  2. Step 2: Convert to fraction form
    78.45/117.78 = 61.44/x
  3. Step 3: Cross multiply
    78.45x = 117.78 × 61.44
  4. Step 4: Simplify right side
    78.45x = 7,236.40
  5. Step 5: Solve for x
    x = 7,236.40/78.45
  6. Step 6: Final answer
    x = 92.24

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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.