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Finding the Fourth Proportional to 82.90, 124.54 and 72.20

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Solution

The fourth proportional to 82.90, 124.54 and 72.20 is: 108.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.90 : 124.54 = 72.20 : x
  2. Step 2: Convert to fraction form
    82.90/124.54 = 72.20/x
  3. Step 3: Cross multiply
    82.90x = 124.54 × 72.20
  4. Step 4: Simplify right side
    82.90x = 8,991.79
  5. Step 5: Solve for x
    x = 8,991.79/82.90
  6. Step 6: Final answer
    x = 108.47

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.