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Finding the Fourth Proportional to 817.21, 1,127.65 and 485.58

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Solution

The fourth proportional to 817.21, 1,127.65 and 485.58 is: 670.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.21 : 1,127.65 = 485.58 : x
  2. Step 2: Convert to fraction form
    817.21/1,127.65 = 485.58/x
  3. Step 3: Cross multiply
    817.21x = 1,127.65 × 485.58
  4. Step 4: Simplify right side
    817.21x = 547,564.29
  5. Step 5: Solve for x
    x = 547,564.29/817.21
  6. Step 6: Final answer
    x = 670.04

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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.