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Finding the Fourth Proportional to 459.70, 689.90 and 216.40

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Solution

The fourth proportional to 459.70, 689.90 and 216.40 is: 324.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    459.70 : 689.90 = 216.40 : x
  2. Step 2: Convert to fraction form
    459.70/689.90 = 216.40/x
  3. Step 3: Cross multiply
    459.70x = 689.90 × 216.40
  4. Step 4: Simplify right side
    459.70x = 149,294.36
  5. Step 5: Solve for x
    x = 149,294.36/459.70
  6. Step 6: Final answer
    x = 324.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.