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Finding the Fourth Proportional to 401.88, 602.80 and 128.20

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Solution

The fourth proportional to 401.88, 602.80 and 128.20 is: 192.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    401.88 : 602.80 = 128.20 : x
  2. Step 2: Convert to fraction form
    401.88/602.80 = 128.20/x
  3. Step 3: Cross multiply
    401.88x = 602.80 × 128.20
  4. Step 4: Simplify right side
    401.88x = 77,278.96
  5. Step 5: Solve for x
    x = 77,278.96/401.88
  6. Step 6: Final answer
    x = 192.29

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.