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Finding the Fourth Proportional to 869.71, 1,200.15 and 491.59

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Solution

The fourth proportional to 869.71, 1,200.15 and 491.59 is: 678.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.71 : 1,200.15 = 491.59 : x
  2. Step 2: Convert to fraction form
    869.71/1,200.15 = 491.59/x
  3. Step 3: Cross multiply
    869.71x = 1,200.15 × 491.59
  4. Step 4: Simplify right side
    869.71x = 589,983.58
  5. Step 5: Solve for x
    x = 589,983.58/869.71
  6. Step 6: Final answer
    x = 678.37

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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.