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Finding the Fourth Proportional to 83.64, 115.28 and 64.20

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Solution

The fourth proportional to 83.64, 115.28 and 64.20 is: 88.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.64 : 115.28 = 64.20 : x
  2. Step 2: Convert to fraction form
    83.64/115.28 = 64.20/x
  3. Step 3: Cross multiply
    83.64x = 115.28 × 64.20
  4. Step 4: Simplify right side
    83.64x = 7,400.98
  5. Step 5: Solve for x
    x = 7,400.98/83.64
  6. Step 6: Final answer
    x = 88.49

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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.