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Finding the Fourth Proportional to 128.76, 177.53 and 109.05

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Solution

The fourth proportional to 128.76, 177.53 and 109.05 is: 150.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.76 : 177.53 = 109.05 : x
  2. Step 2: Convert to fraction form
    128.76/177.53 = 109.05/x
  3. Step 3: Cross multiply
    128.76x = 177.53 × 109.05
  4. Step 4: Simplify right side
    128.76x = 19,359.65
  5. Step 5: Solve for x
    x = 19,359.65/128.76
  6. Step 6: Final answer
    x = 150.35

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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.