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Finding the Fourth Proportional to 207.07, 285.63 and 128.43

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Solution

The fourth proportional to 207.07, 285.63 and 128.43 is: 177.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.07 : 285.63 = 128.43 : x
  2. Step 2: Convert to fraction form
    207.07/285.63 = 128.43/x
  3. Step 3: Cross multiply
    207.07x = 285.63 × 128.43
  4. Step 4: Simplify right side
    207.07x = 36,683.46
  5. Step 5: Solve for x
    x = 36,683.46/207.07
  6. Step 6: Final answer
    x = 177.15

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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.