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Finding the Fourth Proportional to 79.90, 120.46 and 72.07

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Solution

The fourth proportional to 79.90, 120.46 and 72.07 is: 108.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.90 : 120.46 = 72.07 : x
  2. Step 2: Convert to fraction form
    79.90/120.46 = 72.07/x
  3. Step 3: Cross multiply
    79.90x = 120.46 × 72.07
  4. Step 4: Simplify right side
    79.90x = 8,681.55
  5. Step 5: Solve for x
    x = 8,681.55/79.90
  6. Step 6: Final answer
    x = 108.66

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.