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Finding the Fourth Proportional to 1,138.34, 1,706.30 and 812.72

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Solution

The fourth proportional to 1,138.34, 1,706.30 and 812.72 is: 1,218.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,138.34 : 1,706.30 = 812.72 : x
  2. Step 2: Convert to fraction form
    1,138.34/1,706.30 = 812.72/x
  3. Step 3: Cross multiply
    1,138.34x = 1,706.30 × 812.72
  4. Step 4: Simplify right side
    1,138.34x = 1,386,744.14
  5. Step 5: Solve for x
    x = 1,386,744.14/1,138.34
  6. Step 6: Final answer
    x = 1,218.22

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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.