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Finding the Fourth Proportional to 619.21, 854.85 and 421.11

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Solution

The fourth proportional to 619.21, 854.85 and 421.11 is: 581.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.21 : 854.85 = 421.11 : x
  2. Step 2: Convert to fraction form
    619.21/854.85 = 421.11/x
  3. Step 3: Cross multiply
    619.21x = 854.85 × 421.11
  4. Step 4: Simplify right side
    619.21x = 359,986.00
  5. Step 5: Solve for x
    x = 359,986.00/619.21
  6. Step 6: Final answer
    x = 581.36

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.