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Finding the Fourth Proportional to 421.02, 631.57 and 143.57

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Solution

The fourth proportional to 421.02, 631.57 and 143.57 is: 215.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.02 : 631.57 = 143.57 : x
  2. Step 2: Convert to fraction form
    421.02/631.57 = 143.57/x
  3. Step 3: Cross multiply
    421.02x = 631.57 × 143.57
  4. Step 4: Simplify right side
    421.02x = 90,673.54
  5. Step 5: Solve for x
    x = 90,673.54/421.02
  6. Step 6: Final answer
    x = 215.37

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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.