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Finding the Fourth Proportional to 398.58, 549.94 and 305.42

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Solution

The fourth proportional to 398.58, 549.94 and 305.42 is: 421.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.58 : 549.94 = 305.42 : x
  2. Step 2: Convert to fraction form
    398.58/549.94 = 305.42/x
  3. Step 3: Cross multiply
    398.58x = 549.94 × 305.42
  4. Step 4: Simplify right side
    398.58x = 167,962.67
  5. Step 5: Solve for x
    x = 167,962.67/398.58
  6. Step 6: Final answer
    x = 421.40

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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.