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Finding the Fourth Proportional to 619.21, 854.37 and 420.07

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Solution

The fourth proportional to 619.21, 854.37 and 420.07 is: 579.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.21 : 854.37 = 420.07 : x
  2. Step 2: Convert to fraction form
    619.21/854.37 = 420.07/x
  3. Step 3: Cross multiply
    619.21x = 854.37 × 420.07
  4. Step 4: Simplify right side
    619.21x = 358,897.85
  5. Step 5: Solve for x
    x = 358,897.85/619.21
  6. Step 6: Final answer
    x = 579.60

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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.