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Finding the Fourth Proportional to 864.81, 1,297.90 and 378.21

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Solution

The fourth proportional to 864.81, 1,297.90 and 378.21 is: 567.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.81 : 1,297.90 = 378.21 : x
  2. Step 2: Convert to fraction form
    864.81/1,297.90 = 378.21/x
  3. Step 3: Cross multiply
    864.81x = 1,297.90 × 378.21
  4. Step 4: Simplify right side
    864.81x = 490,878.76
  5. Step 5: Solve for x
    x = 490,878.76/864.81
  6. Step 6: Final answer
    x = 567.61

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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.