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Finding the Fourth Proportional to 897.85, 1,238.68 and 687.81

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Solution

The fourth proportional to 897.85, 1,238.68 and 687.81 is: 948.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    897.85 : 1,238.68 = 687.81 : x
  2. Step 2: Convert to fraction form
    897.85/1,238.68 = 687.81/x
  3. Step 3: Cross multiply
    897.85x = 1,238.68 × 687.81
  4. Step 4: Simplify right side
    897.85x = 851,976.49
  5. Step 5: Solve for x
    x = 851,976.49/897.85
  6. Step 6: Final answer
    x = 948.91

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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.