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Finding the Fourth Proportional to 457.14, 685.65 and 128.10

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Solution

The fourth proportional to 457.14, 685.65 and 128.10 is: 192.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    457.14 : 685.65 = 128.10 : x
  2. Step 2: Convert to fraction form
    457.14/685.65 = 128.10/x
  3. Step 3: Cross multiply
    457.14x = 685.65 × 128.10
  4. Step 4: Simplify right side
    457.14x = 87,831.77
  5. Step 5: Solve for x
    x = 87,831.77/457.14
  6. Step 6: Final answer
    x = 192.13

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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.