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Finding the Fourth Proportional to 86.60, 119.70 and 74.30

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Solution

The fourth proportional to 86.60, 119.70 and 74.30 is: 102.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.60 : 119.70 = 74.30 : x
  2. Step 2: Convert to fraction form
    86.60/119.70 = 74.30/x
  3. Step 3: Cross multiply
    86.60x = 119.70 × 74.30
  4. Step 4: Simplify right side
    86.60x = 8,893.71
  5. Step 5: Solve for x
    x = 8,893.71/86.60
  6. Step 6: Final answer
    x = 102.70

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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.