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Finding the Fourth Proportional to 84.20, 116.20 and 64.56

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Solution

The fourth proportional to 84.20, 116.20 and 64.56 is: 89.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.20 : 116.20 = 64.56 : x
  2. Step 2: Convert to fraction form
    84.20/116.20 = 64.56/x
  3. Step 3: Cross multiply
    84.20x = 116.20 × 64.56
  4. Step 4: Simplify right side
    84.20x = 7,501.29
  5. Step 5: Solve for x
    x = 7,501.29/84.20
  6. Step 6: Final answer
    x = 89.09

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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.