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Finding the Fourth Proportional to 144.45, 215.64 and 128.25

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Solution

The fourth proportional to 144.45, 215.64 and 128.25 is: 191.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    144.45 : 215.64 = 128.25 : x
  2. Step 2: Convert to fraction form
    144.45/215.64 = 128.25/x
  3. Step 3: Cross multiply
    144.45x = 215.64 × 128.25
  4. Step 4: Simplify right side
    144.45x = 27,655.83
  5. Step 5: Solve for x
    x = 27,655.83/144.45
  6. Step 6: Final answer
    x = 191.46

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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.