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Finding the Fourth Proportional to 718.85, 1,078.16 and 280.31

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Solution

The fourth proportional to 718.85, 1,078.16 and 280.31 is: 420.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.85 : 1,078.16 = 280.31 : x
  2. Step 2: Convert to fraction form
    718.85/1,078.16 = 280.31/x
  3. Step 3: Cross multiply
    718.85x = 1,078.16 × 280.31
  4. Step 4: Simplify right side
    718.85x = 302,212.24
  5. Step 5: Solve for x
    x = 302,212.24/718.85
  6. Step 6: Final answer
    x = 420.41

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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.