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Finding the Fourth Proportional to 685.09, 1,026.81 and 315.16

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Solution

The fourth proportional to 685.09, 1,026.81 and 315.16 is: 472.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.09 : 1,026.81 = 315.16 : x
  2. Step 2: Convert to fraction form
    685.09/1,026.81 = 315.16/x
  3. Step 3: Cross multiply
    685.09x = 1,026.81 × 315.16
  4. Step 4: Simplify right side
    685.09x = 323,606.87
  5. Step 5: Solve for x
    x = 323,606.87/685.09
  6. Step 6: Final answer
    x = 472.36

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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.