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Finding the Fourth Proportional to 1,213.79, 1,675.15 and 689.72

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Solution

The fourth proportional to 1,213.79, 1,675.15 and 689.72 is: 951.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,213.79 : 1,675.15 = 689.72 : x
  2. Step 2: Convert to fraction form
    1,213.79/1,675.15 = 689.72/x
  3. Step 3: Cross multiply
    1,213.79x = 1,675.15 × 689.72
  4. Step 4: Simplify right side
    1,213.79x = 1,155,374.36
  5. Step 5: Solve for x
    x = 1,155,374.36/1,213.79
  6. Step 6: Final answer
    x = 951.88

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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.