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Finding the Fourth Proportional to 685.36, 1,028.16 and 442.12

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Solution

The fourth proportional to 685.36, 1,028.16 and 442.12 is: 663.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.36 : 1,028.16 = 442.12 : x
  2. Step 2: Convert to fraction form
    685.36/1,028.16 = 442.12/x
  3. Step 3: Cross multiply
    685.36x = 1,028.16 × 442.12
  4. Step 4: Simplify right side
    685.36x = 454,570.10
  5. Step 5: Solve for x
    x = 454,570.10/685.36
  6. Step 6: Final answer
    x = 663.26

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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.