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Finding the Fourth Proportional to 151.76, 209.16 and 128.51

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Solution

The fourth proportional to 151.76, 209.16 and 128.51 is: 177.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.76 : 209.16 = 128.51 : x
  2. Step 2: Convert to fraction form
    151.76/209.16 = 128.51/x
  3. Step 3: Cross multiply
    151.76x = 209.16 × 128.51
  4. Step 4: Simplify right side
    151.76x = 26,878.11
  5. Step 5: Solve for x
    x = 26,878.11/151.76
  6. Step 6: Final answer
    x = 177.12

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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.