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Finding the Fourth Proportional to 86.70, 119.70 and 64.62

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Solution

The fourth proportional to 86.70, 119.70 and 64.62 is: 89.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.70 : 119.70 = 64.62 : x
  2. Step 2: Convert to fraction form
    86.70/119.70 = 64.62/x
  3. Step 3: Cross multiply
    86.70x = 119.70 × 64.62
  4. Step 4: Simplify right side
    86.70x = 7,735.01
  5. Step 5: Solve for x
    x = 7,735.01/86.70
  6. Step 6: Final answer
    x = 89.22

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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.