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Finding the Fourth Proportional to 879.39, 1,317.82 and 385.20

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Solution

The fourth proportional to 879.39, 1,317.82 and 385.20 is: 577.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.39 : 1,317.82 = 385.20 : x
  2. Step 2: Convert to fraction form
    879.39/1,317.82 = 385.20/x
  3. Step 3: Cross multiply
    879.39x = 1,317.82 × 385.20
  4. Step 4: Simplify right side
    879.39x = 507,624.26
  5. Step 5: Solve for x
    x = 507,624.26/879.39
  6. Step 6: Final answer
    x = 577.25

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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.