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Finding the Fourth Proportional to 85.86, 118.62 and 72.18

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Solution

The fourth proportional to 85.86, 118.62 and 72.18 is: 99.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.86 : 118.62 = 72.18 : x
  2. Step 2: Convert to fraction form
    85.86/118.62 = 72.18/x
  3. Step 3: Cross multiply
    85.86x = 118.62 × 72.18
  4. Step 4: Simplify right side
    85.86x = 8,561.99
  5. Step 5: Solve for x
    x = 8,561.99/85.86
  6. Step 6: Final answer
    x = 99.72

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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.