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Finding the Fourth Proportional to 287.30, 430.60 and 142.71

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Solution

The fourth proportional to 287.30, 430.60 and 142.71 is: 213.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.30 : 430.60 = 142.71 : x
  2. Step 2: Convert to fraction form
    287.30/430.60 = 142.71/x
  3. Step 3: Cross multiply
    287.30x = 430.60 × 142.71
  4. Step 4: Simplify right side
    287.30x = 61,450.93
  5. Step 5: Solve for x
    x = 61,450.93/287.30
  6. Step 6: Final answer
    x = 213.89

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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.