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Finding the Fourth Proportional to 399.63, 599.31 and 139.53

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Solution

The fourth proportional to 399.63, 599.31 and 139.53 is: 209.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.63 : 599.31 = 139.53 : x
  2. Step 2: Convert to fraction form
    399.63/599.31 = 139.53/x
  3. Step 3: Cross multiply
    399.63x = 599.31 × 139.53
  4. Step 4: Simplify right side
    399.63x = 83,621.72
  5. Step 5: Solve for x
    x = 83,621.72/399.63
  6. Step 6: Final answer
    x = 209.25

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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.