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Finding the Fourth Proportional to 399.30, 598.71 and 139.17

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Solution

The fourth proportional to 399.30, 598.71 and 139.17 is: 208.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.30 : 598.71 = 139.17 : x
  2. Step 2: Convert to fraction form
    399.30/598.71 = 139.17/x
  3. Step 3: Cross multiply
    399.30x = 598.71 × 139.17
  4. Step 4: Simplify right side
    399.30x = 83,322.47
  5. Step 5: Solve for x
    x = 83,322.47/399.30
  6. Step 6: Final answer
    x = 208.67

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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.