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Finding the Fourth Proportional to 63.85, 88.10 and 39.28

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Solution

The fourth proportional to 63.85, 88.10 and 39.28 is: 54.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.85 : 88.10 = 39.28 : x
  2. Step 2: Convert to fraction form
    63.85/88.10 = 39.28/x
  3. Step 3: Cross multiply
    63.85x = 88.10 × 39.28
  4. Step 4: Simplify right side
    63.85x = 3,460.57
  5. Step 5: Solve for x
    x = 3,460.57/63.85
  6. Step 6: Final answer
    x = 54.20

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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.