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Finding the Fourth Proportional to 85.09, 117.46 and 71.79

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Solution

The fourth proportional to 85.09, 117.46 and 71.79 is: 99.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.09 : 117.46 = 71.79 : x
  2. Step 2: Convert to fraction form
    85.09/117.46 = 71.79/x
  3. Step 3: Cross multiply
    85.09x = 117.46 × 71.79
  4. Step 4: Simplify right side
    85.09x = 8,432.45
  5. Step 5: Solve for x
    x = 8,432.45/85.09
  6. Step 6: Final answer
    x = 99.10

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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.