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Finding the Fourth Proportional to 79.09, 109.01 and 72.20

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Solution

The fourth proportional to 79.09, 109.01 and 72.20 is: 99.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.09 : 109.01 = 72.20 : x
  2. Step 2: Convert to fraction form
    79.09/109.01 = 72.20/x
  3. Step 3: Cross multiply
    79.09x = 109.01 × 72.20
  4. Step 4: Simplify right side
    79.09x = 7,870.16
  5. Step 5: Solve for x
    x = 7,870.16/79.09
  6. Step 6: Final answer
    x = 99.52

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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.