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Finding the Fourth Proportional to 812.40, 1,217.38 and 751.65

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Solution

The fourth proportional to 812.40, 1,217.38 and 751.65 is: 1,126.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.40 : 1,217.38 = 751.65 : x
  2. Step 2: Convert to fraction form
    812.40/1,217.38 = 751.65/x
  3. Step 3: Cross multiply
    812.40x = 1,217.38 × 751.65
  4. Step 4: Simplify right side
    812.40x = 915,038.64
  5. Step 5: Solve for x
    x = 915,038.64/812.40
  6. Step 6: Final answer
    x = 1,126.35

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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.