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Finding the Fourth Proportional to 421.58, 631.40 and 247.91

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Solution

The fourth proportional to 421.58, 631.40 and 247.91 is: 371.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.58 : 631.40 = 247.91 : x
  2. Step 2: Convert to fraction form
    421.58/631.40 = 247.91/x
  3. Step 3: Cross multiply
    421.58x = 631.40 × 247.91
  4. Step 4: Simplify right side
    421.58x = 156,525.98
  5. Step 5: Solve for x
    x = 156,525.98/421.58
  6. Step 6: Final answer
    x = 371.28

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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.