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Finding the Fourth Proportional to 1,380.60, 2,070.89 and 407.38

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Solution

The fourth proportional to 1,380.60, 2,070.89 and 407.38 is: 611.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,380.60 : 2,070.89 = 407.38 : x
  2. Step 2: Convert to fraction form
    1,380.60/2,070.89 = 407.38/x
  3. Step 3: Cross multiply
    1,380.60x = 2,070.89 × 407.38
  4. Step 4: Simplify right side
    1,380.60x = 843,639.17
  5. Step 5: Solve for x
    x = 843,639.17/1,380.60
  6. Step 6: Final answer
    x = 611.07

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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.