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Finding the Fourth Proportional to 815.70, 1,223.55 and 540.90

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Solution

The fourth proportional to 815.70, 1,223.55 and 540.90 is: 811.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.70 : 1,223.55 = 540.90 : x
  2. Step 2: Convert to fraction form
    815.70/1,223.55 = 540.90/x
  3. Step 3: Cross multiply
    815.70x = 1,223.55 × 540.90
  4. Step 4: Simplify right side
    815.70x = 661,818.20
  5. Step 5: Solve for x
    x = 661,818.20/815.70
  6. Step 6: Final answer
    x = 811.35

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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.