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Finding the Fourth Proportional to 128.70, 176.40 and 127.08

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Solution

The fourth proportional to 128.70, 176.40 and 127.08 is: 174.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.70 : 176.40 = 127.08 : x
  2. Step 2: Convert to fraction form
    128.70/176.40 = 127.08/x
  3. Step 3: Cross multiply
    128.70x = 176.40 × 127.08
  4. Step 4: Simplify right side
    128.70x = 22,416.91
  5. Step 5: Solve for x
    x = 22,416.91/128.70
  6. Step 6: Final answer
    x = 174.18

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.