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Finding the Fourth Proportional to 1,242.56, 1,863.84 and 421.76

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Solution

The fourth proportional to 1,242.56, 1,863.84 and 421.76 is: 632.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,242.56 : 1,863.84 = 421.76 : x
  2. Step 2: Convert to fraction form
    1,242.56/1,863.84 = 421.76/x
  3. Step 3: Cross multiply
    1,242.56x = 1,863.84 × 421.76
  4. Step 4: Simplify right side
    1,242.56x = 786,093.16
  5. Step 5: Solve for x
    x = 786,093.16/1,242.56
  6. Step 6: Final answer
    x = 632.64

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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.