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Finding the Fourth Proportional to 816.88, 1,127.21 and 485.25

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Solution

The fourth proportional to 816.88, 1,127.21 and 485.25 is: 669.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.88 : 1,127.21 = 485.25 : x
  2. Step 2: Convert to fraction form
    816.88/1,127.21 = 485.25/x
  3. Step 3: Cross multiply
    816.88x = 1,127.21 × 485.25
  4. Step 4: Simplify right side
    816.88x = 546,978.65
  5. Step 5: Solve for x
    x = 546,978.65/816.88
  6. Step 6: Final answer
    x = 669.59

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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.