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Finding the Fourth Proportional to 431.08, 647.32 and 399.10

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Solution

The fourth proportional to 431.08, 647.32 and 399.10 is: 599.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.08 : 647.32 = 399.10 : x
  2. Step 2: Convert to fraction form
    431.08/647.32 = 399.10/x
  3. Step 3: Cross multiply
    431.08x = 647.32 × 399.10
  4. Step 4: Simplify right side
    431.08x = 258,345.41
  5. Step 5: Solve for x
    x = 258,345.41/431.08
  6. Step 6: Final answer
    x = 599.30

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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.