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Finding the Fourth Proportional to 85.09, 117.34 and 72.85

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Solution

The fourth proportional to 85.09, 117.34 and 72.85 is: 100.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.09 : 117.34 = 72.85 : x
  2. Step 2: Convert to fraction form
    85.09/117.34 = 72.85/x
  3. Step 3: Cross multiply
    85.09x = 117.34 × 72.85
  4. Step 4: Simplify right side
    85.09x = 8,548.22
  5. Step 5: Solve for x
    x = 8,548.22/85.09
  6. Step 6: Final answer
    x = 100.46

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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.