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Finding the Fourth Proportional to 815.55, 1,223.43 and 260.19

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Solution

The fourth proportional to 815.55, 1,223.43 and 260.19 is: 390.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.55 : 1,223.43 = 260.19 : x
  2. Step 2: Convert to fraction form
    815.55/1,223.43 = 260.19/x
  3. Step 3: Cross multiply
    815.55x = 1,223.43 × 260.19
  4. Step 4: Simplify right side
    815.55x = 318,324.25
  5. Step 5: Solve for x
    x = 318,324.25/815.55
  6. Step 6: Final answer
    x = 390.32

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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.