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Finding the Fourth Proportional to 88.90, 122.72 and 56.20

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Solution

The fourth proportional to 88.90, 122.72 and 56.20 is: 77.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.90 : 122.72 = 56.20 : x
  2. Step 2: Convert to fraction form
    88.90/122.72 = 56.20/x
  3. Step 3: Cross multiply
    88.90x = 122.72 × 56.20
  4. Step 4: Simplify right side
    88.90x = 6,896.58
  5. Step 5: Solve for x
    x = 6,896.58/88.90
  6. Step 6: Final answer
    x = 77.58

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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.