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Finding the Fourth Proportional to 99.80, 149.01 and 79.28

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Solution

The fourth proportional to 99.80, 149.01 and 79.28 is: 118.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.80 : 149.01 = 79.28 : x
  2. Step 2: Convert to fraction form
    99.80/149.01 = 79.28/x
  3. Step 3: Cross multiply
    99.80x = 149.01 × 79.28
  4. Step 4: Simplify right side
    99.80x = 11,812.77
  5. Step 5: Solve for x
    x = 11,812.77/99.80
  6. Step 6: Final answer
    x = 118.37

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.