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Finding the Fourth Proportional to 1,321.07, 1,980.50 and 728.02

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Solution

The fourth proportional to 1,321.07, 1,980.50 and 728.02 is: 1,091.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,321.07 : 1,980.50 = 728.02 : x
  2. Step 2: Convert to fraction form
    1,321.07/1,980.50 = 728.02/x
  3. Step 3: Cross multiply
    1,321.07x = 1,980.50 × 728.02
  4. Step 4: Simplify right side
    1,321.07x = 1,441,835.02
  5. Step 5: Solve for x
    x = 1,441,835.02/1,321.07
  6. Step 6: Final answer
    x = 1,091.41

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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.