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Finding the Fourth Proportional to 128.16, 190.71 and 123.75

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Solution

The fourth proportional to 128.16, 190.71 and 123.75 is: 184.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.16 : 190.71 = 123.75 : x
  2. Step 2: Convert to fraction form
    128.16/190.71 = 123.75/x
  3. Step 3: Cross multiply
    128.16x = 190.71 × 123.75
  4. Step 4: Simplify right side
    128.16x = 23,600.36
  5. Step 5: Solve for x
    x = 23,600.36/128.16
  6. Step 6: Final answer
    x = 184.15

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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.