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Finding the Fourth Proportional to 147.39, 219.99 and 128.19

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Solution

The fourth proportional to 147.39, 219.99 and 128.19 is: 191.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    147.39 : 219.99 = 128.19 : x
  2. Step 2: Convert to fraction form
    147.39/219.99 = 128.19/x
  3. Step 3: Cross multiply
    147.39x = 219.99 × 128.19
  4. Step 4: Simplify right side
    147.39x = 28,200.52
  5. Step 5: Solve for x
    x = 28,200.52/147.39
  6. Step 6: Final answer
    x = 191.33

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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.