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Finding the Fourth Proportional to 781.99, 1,078.38 and 479.07

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Solution

The fourth proportional to 781.99, 1,078.38 and 479.07 is: 660.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.99 : 1,078.38 = 479.07 : x
  2. Step 2: Convert to fraction form
    781.99/1,078.38 = 479.07/x
  3. Step 3: Cross multiply
    781.99x = 1,078.38 × 479.07
  4. Step 4: Simplify right side
    781.99x = 516,619.51
  5. Step 5: Solve for x
    x = 516,619.51/781.99
  6. Step 6: Final answer
    x = 660.65

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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.