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Finding the Fourth Proportional to 685.68, 1,029.87 and 666.51

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Solution

The fourth proportional to 685.68, 1,029.87 and 666.51 is: 1,001.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.68 : 1,029.87 = 666.51 : x
  2. Step 2: Convert to fraction form
    685.68/1,029.87 = 666.51/x
  3. Step 3: Cross multiply
    685.68x = 1,029.87 × 666.51
  4. Step 4: Simplify right side
    685.68x = 686,418.65
  5. Step 5: Solve for x
    x = 686,418.65/685.68
  6. Step 6: Final answer
    x = 1,001.08

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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.