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Finding the Fourth Proportional to 718.72, 1,078.05 and 256.81

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Solution

The fourth proportional to 718.72, 1,078.05 and 256.81 is: 385.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    718.72 : 1,078.05 = 256.81 : x
  2. Step 2: Convert to fraction form
    718.72/1,078.05 = 256.81/x
  3. Step 3: Cross multiply
    718.72x = 1,078.05 × 256.81
  4. Step 4: Simplify right side
    718.72x = 276,854.02
  5. Step 5: Solve for x
    x = 276,854.02/718.72
  6. Step 6: Final answer
    x = 385.20

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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.