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Finding the Fourth Proportional to 816.83, 1,127.15 and 485.21

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Solution

The fourth proportional to 816.83, 1,127.15 and 485.21 is: 669.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    816.83 : 1,127.15 = 485.21 : x
  2. Step 2: Convert to fraction form
    816.83/1,127.15 = 485.21/x
  3. Step 3: Cross multiply
    816.83x = 1,127.15 × 485.21
  4. Step 4: Simplify right side
    816.83x = 546,900.32
  5. Step 5: Solve for x
    x = 546,900.32/816.83
  6. Step 6: Final answer
    x = 669.54

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Double scale
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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.