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Finding the Fourth Proportional to 215.83, 297.80 and 128.51

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Solution

The fourth proportional to 215.83, 297.80 and 128.51 is: 177.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.83 : 297.80 = 128.51 : x
  2. Step 2: Convert to fraction form
    215.83/297.80 = 128.51/x
  3. Step 3: Cross multiply
    215.83x = 297.80 × 128.51
  4. Step 4: Simplify right side
    215.83x = 38,270.28
  5. Step 5: Solve for x
    x = 38,270.28/215.83
  6. Step 6: Final answer
    x = 177.32

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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.