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Finding the Fourth Proportional to 285.71, 428.56 and 129.45

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Solution

The fourth proportional to 285.71, 428.56 and 129.45 is: 194.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.71 : 428.56 = 129.45 : x
  2. Step 2: Convert to fraction form
    285.71/428.56 = 129.45/x
  3. Step 3: Cross multiply
    285.71x = 428.56 × 129.45
  4. Step 4: Simplify right side
    285.71x = 55,476.24
  5. Step 5: Solve for x
    x = 55,476.24/285.71
  6. Step 6: Final answer
    x = 194.17

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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.