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Finding the Fourth Proportional to 718.81, 1,078.41 and 389.67

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Solution

The fourth proportional to 718.81, 1,078.41 and 389.67 is: 584.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.81 : 1,078.41 = 389.67 : x
  2. Step 2: Convert to fraction form
    718.81/1,078.41 = 389.67/x
  3. Step 3: Cross multiply
    718.81x = 1,078.41 × 389.67
  4. Step 4: Simplify right side
    718.81x = 420,227.51
  5. Step 5: Solve for x
    x = 420,227.51/718.81
  6. Step 6: Final answer
    x = 584.61

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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.