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Finding the Fourth Proportional to 398.10, 549.21 and 287.33

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Solution

The fourth proportional to 398.10, 549.21 and 287.33 is: 396.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.10 : 549.21 = 287.33 : x
  2. Step 2: Convert to fraction form
    398.10/549.21 = 287.33/x
  3. Step 3: Cross multiply
    398.10x = 549.21 × 287.33
  4. Step 4: Simplify right side
    398.10x = 157,804.31
  5. Step 5: Solve for x
    x = 157,804.31/398.10
  6. Step 6: Final answer
    x = 396.40

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.