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Finding the Fourth Proportional to 1,321.30, 1,823.40 and 723.80

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Solution

The fourth proportional to 1,321.30, 1,823.40 and 723.80 is: 998.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,321.30 : 1,823.40 = 723.80 : x
  2. Step 2: Convert to fraction form
    1,321.30/1,823.40 = 723.80/x
  3. Step 3: Cross multiply
    1,321.30x = 1,823.40 × 723.80
  4. Step 4: Simplify right side
    1,321.30x = 1,319,776.92
  5. Step 5: Solve for x
    x = 1,319,776.92/1,321.30
  6. Step 6: Final answer
    x = 998.85

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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.