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Finding the Fourth Proportional to 85.78, 118.26 and 61.22

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Solution

The fourth proportional to 85.78, 118.26 and 61.22 is: 84.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.78 : 118.26 = 61.22 : x
  2. Step 2: Convert to fraction form
    85.78/118.26 = 61.22/x
  3. Step 3: Cross multiply
    85.78x = 118.26 × 61.22
  4. Step 4: Simplify right side
    85.78x = 7,239.88
  5. Step 5: Solve for x
    x = 7,239.88/85.78
  6. Step 6: Final answer
    x = 84.40

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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.