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Finding the Fourth Proportional to 398.70, 549.81 and 258.90

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Solution

The fourth proportional to 398.70, 549.81 and 258.90 is: 357.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.70 : 549.81 = 258.90 : x
  2. Step 2: Convert to fraction form
    398.70/549.81 = 258.90/x
  3. Step 3: Cross multiply
    398.70x = 549.81 × 258.90
  4. Step 4: Simplify right side
    398.70x = 142,345.81
  5. Step 5: Solve for x
    x = 142,345.81/398.70
  6. Step 6: Final answer
    x = 357.02

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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.