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Finding the Fourth Proportional to 872.94, 1,309.86 and 386.31

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Solution

The fourth proportional to 872.94, 1,309.86 and 386.31 is: 579.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.94 : 1,309.86 = 386.31 : x
  2. Step 2: Convert to fraction form
    872.94/1,309.86 = 386.31/x
  3. Step 3: Cross multiply
    872.94x = 1,309.86 × 386.31
  4. Step 4: Simplify right side
    872.94x = 506,012.02
  5. Step 5: Solve for x
    x = 506,012.02/872.94
  6. Step 6: Final answer
    x = 579.66

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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.