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Finding the Fourth Proportional to 891.70, 1,230.63 and 518.65

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Solution

The fourth proportional to 891.70, 1,230.63 and 518.65 is: 715.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.70 : 1,230.63 = 518.65 : x
  2. Step 2: Convert to fraction form
    891.70/1,230.63 = 518.65/x
  3. Step 3: Cross multiply
    891.70x = 1,230.63 × 518.65
  4. Step 4: Simplify right side
    891.70x = 638,266.25
  5. Step 5: Solve for x
    x = 638,266.25/891.70
  6. Step 6: Final answer
    x = 715.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.