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Finding the Fourth Proportional to 74.63, 103.21 and 56.21

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Solution

The fourth proportional to 74.63, 103.21 and 56.21 is: 77.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    74.63 : 103.21 = 56.21 : x
  2. Step 2: Convert to fraction form
    74.63/103.21 = 56.21/x
  3. Step 3: Cross multiply
    74.63x = 103.21 × 56.21
  4. Step 4: Simplify right side
    74.63x = 5,800.78
  5. Step 5: Solve for x
    x = 5,800.78/74.63
  6. Step 6: Final answer
    x = 77.72

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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.