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Finding the Fourth Proportional to 147.80, 221.81 and 99.15

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Solution

The fourth proportional to 147.80, 221.81 and 99.15 is: 148.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    147.80 : 221.81 = 99.15 : x
  2. Step 2: Convert to fraction form
    147.80/221.81 = 99.15/x
  3. Step 3: Cross multiply
    147.80x = 221.81 × 99.15
  4. Step 4: Simplify right side
    147.80x = 21,991.69
  5. Step 5: Solve for x
    x = 21,991.69/147.80
  6. Step 6: Final answer
    x = 148.79

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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.