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Finding the Fourth Proportional to 1,387.64, 2,080.05 and 657.83

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Solution

The fourth proportional to 1,387.64, 2,080.05 and 657.83 is: 986.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,387.64 : 2,080.05 = 657.83 : x
  2. Step 2: Convert to fraction form
    1,387.64/2,080.05 = 657.83/x
  3. Step 3: Cross multiply
    1,387.64x = 2,080.05 × 657.83
  4. Step 4: Simplify right side
    1,387.64x = 1,368,321.20
  5. Step 5: Solve for x
    x = 1,368,321.20/1,387.64
  6. Step 6: Final answer
    x = 986.08

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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.