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Finding the Fourth Proportional to 816.77, 1,127.12 and 485.21

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Solution

The fourth proportional to 816.77, 1,127.12 and 485.21 is: 669.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.77 : 1,127.12 = 485.21 : x
  2. Step 2: Convert to fraction form
    816.77/1,127.12 = 485.21/x
  3. Step 3: Cross multiply
    816.77x = 1,127.12 × 485.21
  4. Step 4: Simplify right side
    816.77x = 546,893.93
  5. Step 5: Solve for x
    x = 546,893.93/816.77
  6. Step 6: Final answer
    x = 669.58

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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.