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Finding the Fourth Proportional to 85.47, 117.68 and 69.15

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Solution

The fourth proportional to 85.47, 117.68 and 69.15 is: 95.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.47 : 117.68 = 69.15 : x
  2. Step 2: Convert to fraction form
    85.47/117.68 = 69.15/x
  3. Step 3: Cross multiply
    85.47x = 117.68 × 69.15
  4. Step 4: Simplify right side
    85.47x = 8,137.23
  5. Step 5: Solve for x
    x = 8,137.23/85.47
  6. Step 6: Final answer
    x = 95.21

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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.