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Finding the Fourth Proportional to 620.42, 854.72 and 398.98

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Solution

The fourth proportional to 620.42, 854.72 and 398.98 is: 549.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.42 : 854.72 = 398.98 : x
  2. Step 2: Convert to fraction form
    620.42/854.72 = 398.98/x
  3. Step 3: Cross multiply
    620.42x = 854.72 × 398.98
  4. Step 4: Simplify right side
    620.42x = 341,016.76
  5. Step 5: Solve for x
    x = 341,016.76/620.42
  6. Step 6: Final answer
    x = 549.66

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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.