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Finding the Fourth Proportional to 76.98, 106.21 and 45.90

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Solution

The fourth proportional to 76.98, 106.21 and 45.90 is: 63.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.98 : 106.21 = 45.90 : x
  2. Step 2: Convert to fraction form
    76.98/106.21 = 45.90/x
  3. Step 3: Cross multiply
    76.98x = 106.21 × 45.90
  4. Step 4: Simplify right side
    76.98x = 4,875.58
  5. Step 5: Solve for x
    x = 4,875.58/76.98
  6. Step 6: Final answer
    x = 63.34

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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.