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Finding the Fourth Proportional to 840.67, 1,261.01 and 378.20

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Solution

The fourth proportional to 840.67, 1,261.01 and 378.20 is: 567.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.67 : 1,261.01 = 378.20 : x
  2. Step 2: Convert to fraction form
    840.67/1,261.01 = 378.20/x
  3. Step 3: Cross multiply
    840.67x = 1,261.01 × 378.20
  4. Step 4: Simplify right side
    840.67x = 476,918.08
  5. Step 5: Solve for x
    x = 476,918.08/840.67
  6. Step 6: Final answer
    x = 567.31

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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.