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Finding the Fourth Proportional to 688.45, 1,032.64 and 380.45

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Solution

The fourth proportional to 688.45, 1,032.64 and 380.45 is: 570.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.45 : 1,032.64 = 380.45 : x
  2. Step 2: Convert to fraction form
    688.45/1,032.64 = 380.45/x
  3. Step 3: Cross multiply
    688.45x = 1,032.64 × 380.45
  4. Step 4: Simplify right side
    688.45x = 392,865.99
  5. Step 5: Solve for x
    x = 392,865.99/688.45
  6. Step 6: Final answer
    x = 570.66

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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.