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Finding the Fourth Proportional to 1,384.50, 2,076.75 and 643.71

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Solution

The fourth proportional to 1,384.50, 2,076.75 and 643.71 is: 965.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,384.50 : 2,076.75 = 643.71 : x
  2. Step 2: Convert to fraction form
    1,384.50/2,076.75 = 643.71/x
  3. Step 3: Cross multiply
    1,384.50x = 2,076.75 × 643.71
  4. Step 4: Simplify right side
    1,384.50x = 1,336,824.74
  5. Step 5: Solve for x
    x = 1,336,824.74/1,384.50
  6. Step 6: Final answer
    x = 965.57

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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.