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Finding the Fourth Proportional to 919.46, 1,378.38 and 647.30

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Solution

The fourth proportional to 919.46, 1,378.38 and 647.30 is: 970.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.46 : 1,378.38 = 647.30 : x
  2. Step 2: Convert to fraction form
    919.46/1,378.38 = 647.30/x
  3. Step 3: Cross multiply
    919.46x = 1,378.38 × 647.30
  4. Step 4: Simplify right side
    919.46x = 892,225.37
  5. Step 5: Solve for x
    x = 892,225.37/919.46
  6. Step 6: Final answer
    x = 970.38

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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.