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Finding the Fourth Proportional to 1,379.00, 1,902.99 and 781.45

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Solution

The fourth proportional to 1,379.00, 1,902.99 and 781.45 is: 1,078.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.00 : 1,902.99 = 781.45 : x
  2. Step 2: Convert to fraction form
    1,379.00/1,902.99 = 781.45/x
  3. Step 3: Cross multiply
    1,379.00x = 1,902.99 × 781.45
  4. Step 4: Simplify right side
    1,379.00x = 1,487,089.71
  5. Step 5: Solve for x
    x = 1,487,089.71/1,379.00
  6. Step 6: Final answer
    x = 1,078.38

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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.