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Finding the Fourth Proportional to 399.12, 598.76 and 139.11

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Solution

The fourth proportional to 399.12, 598.76 and 139.11 is: 208.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.12 : 598.76 = 139.11 : x
  2. Step 2: Convert to fraction form
    399.12/598.76 = 139.11/x
  3. Step 3: Cross multiply
    399.12x = 598.76 × 139.11
  4. Step 4: Simplify right side
    399.12x = 83,292.81
  5. Step 5: Solve for x
    x = 83,292.81/399.12
  6. Step 6: Final answer
    x = 208.69

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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.