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Finding the Fourth Proportional to 620.08, 855.51 and 398.63

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Solution

The fourth proportional to 620.08, 855.51 and 398.63 is: 549.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.08 : 855.51 = 398.63 : x
  2. Step 2: Convert to fraction form
    620.08/855.51 = 398.63/x
  3. Step 3: Cross multiply
    620.08x = 855.51 × 398.63
  4. Step 4: Simplify right side
    620.08x = 341,031.95
  5. Step 5: Solve for x
    x = 341,031.95/620.08
  6. Step 6: Final answer
    x = 549.98

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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.