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Finding the Fourth Proportional to 869.40, 1,199.10 and 519.72

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Solution

The fourth proportional to 869.40, 1,199.10 and 519.72 is: 716.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    869.40 : 1,199.10 = 519.72 : x
  2. Step 2: Convert to fraction form
    869.40/1,199.10 = 519.72/x
  3. Step 3: Cross multiply
    869.40x = 1,199.10 × 519.72
  4. Step 4: Simplify right side
    869.40x = 623,196.25
  5. Step 5: Solve for x
    x = 623,196.25/869.40
  6. Step 6: Final answer
    x = 716.81

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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.