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Finding the Fourth Proportional to 719.45, 1,078.85 and 257.11

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Solution

The fourth proportional to 719.45, 1,078.85 and 257.11 is: 385.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.45 : 1,078.85 = 257.11 : x
  2. Step 2: Convert to fraction form
    719.45/1,078.85 = 257.11/x
  3. Step 3: Cross multiply
    719.45x = 1,078.85 × 257.11
  4. Step 4: Simplify right side
    719.45x = 277,381.07
  5. Step 5: Solve for x
    x = 277,381.07/719.45
  6. Step 6: Final answer
    x = 385.55

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1.5x scale

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.