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Finding the Fourth Proportional to 128.39, 177.16 and 73.13

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Solution

The fourth proportional to 128.39, 177.16 and 73.13 is: 100.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.39 : 177.16 = 73.13 : x
  2. Step 2: Convert to fraction form
    128.39/177.16 = 73.13/x
  3. Step 3: Cross multiply
    128.39x = 177.16 × 73.13
  4. Step 4: Simplify right side
    128.39x = 12,955.71
  5. Step 5: Solve for x
    x = 12,955.71/128.39
  6. Step 6: Final answer
    x = 100.91

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.