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Finding the Fourth Proportional to 457.36, 686.09 and 128.32

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Solution

The fourth proportional to 457.36, 686.09 and 128.32 is: 192.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    457.36 : 686.09 = 128.32 : x
  2. Step 2: Convert to fraction form
    457.36/686.09 = 128.32/x
  3. Step 3: Cross multiply
    457.36x = 686.09 × 128.32
  4. Step 4: Simplify right side
    457.36x = 88,039.07
  5. Step 5: Solve for x
    x = 88,039.07/457.36
  6. Step 6: Final answer
    x = 192.49

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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.