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Finding the Fourth Proportional to 719.74, 1,079.74 and 286.90

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Solution

The fourth proportional to 719.74, 1,079.74 and 286.90 is: 430.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.74 : 1,079.74 = 286.90 : x
  2. Step 2: Convert to fraction form
    719.74/1,079.74 = 286.90/x
  3. Step 3: Cross multiply
    719.74x = 1,079.74 × 286.90
  4. Step 4: Simplify right side
    719.74x = 309,777.41
  5. Step 5: Solve for x
    x = 309,777.41/719.74
  6. Step 6: Final answer
    x = 430.40

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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.