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Finding the Fourth Proportional to 83.64, 115.40 and 57.47

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Solution

The fourth proportional to 83.64, 115.40 and 57.47 is: 79.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.64 : 115.40 = 57.47 : x
  2. Step 2: Convert to fraction form
    83.64/115.40 = 57.47/x
  3. Step 3: Cross multiply
    83.64x = 115.40 × 57.47
  4. Step 4: Simplify right side
    83.64x = 6,631.17
  5. Step 5: Solve for x
    x = 6,631.17/83.64
  6. Step 6: Final answer
    x = 79.28

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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.