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Finding the Fourth Proportional to 74.20, 102.40 and 63.28

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Solution

The fourth proportional to 74.20, 102.40 and 63.28 is: 87.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.20 : 102.40 = 63.28 : x
  2. Step 2: Convert to fraction form
    74.20/102.40 = 63.28/x
  3. Step 3: Cross multiply
    74.20x = 102.40 × 63.28
  4. Step 4: Simplify right side
    74.20x = 6,479.87
  5. Step 5: Solve for x
    x = 6,479.87/74.20
  6. Step 6: Final answer
    x = 87.33

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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.