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Finding the Fourth Proportional to 215.68, 297.63 and 128.35

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Solution

The fourth proportional to 215.68, 297.63 and 128.35 is: 177.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.68 : 297.63 = 128.35 : x
  2. Step 2: Convert to fraction form
    215.68/297.63 = 128.35/x
  3. Step 3: Cross multiply
    215.68x = 297.63 × 128.35
  4. Step 4: Simplify right side
    215.68x = 38,200.81
  5. Step 5: Solve for x
    x = 38,200.81/215.68
  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.