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Finding the Fourth Proportional to 401.87, 602.78 and 128.16

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Solution

The fourth proportional to 401.87, 602.78 and 128.16 is: 192.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    401.87 : 602.78 = 128.16 : x
  2. Step 2: Convert to fraction form
    401.87/602.78 = 128.16/x
  3. Step 3: Cross multiply
    401.87x = 602.78 × 128.16
  4. Step 4: Simplify right side
    401.87x = 77,248.63
  5. Step 5: Solve for x
    x = 77,248.63/401.87
  6. Step 6: Final answer
    x = 192.23

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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.