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Finding the Fourth Proportional to 905.81, 1,250.02 and 491.81

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Solution

The fourth proportional to 905.81, 1,250.02 and 491.81 is: 678.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    905.81 : 1,250.02 = 491.81 : x
  2. Step 2: Convert to fraction form
    905.81/1,250.02 = 491.81/x
  3. Step 3: Cross multiply
    905.81x = 1,250.02 × 491.81
  4. Step 4: Simplify right side
    905.81x = 614,776.08
  5. Step 5: Solve for x
    x = 614,776.08/905.81
  6. Step 6: Final answer
    x = 678.70

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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.