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Finding the Fourth Proportional to 678.42, 1,017.58 and 216.21

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Solution

The fourth proportional to 678.42, 1,017.58 and 216.21 is: 324.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.42 : 1,017.58 = 216.21 : x
  2. Step 2: Convert to fraction form
    678.42/1,017.58 = 216.21/x
  3. Step 3: Cross multiply
    678.42x = 1,017.58 × 216.21
  4. Step 4: Simplify right side
    678.42x = 220,010.97
  5. Step 5: Solve for x
    x = 220,010.97/678.42
  6. Step 6: Final answer
    x = 324.30

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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.