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Finding the Fourth Proportional to 1,288.73, 1,931.95 and 621.29

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Solution

The fourth proportional to 1,288.73, 1,931.95 and 621.29 is: 931.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,288.73 : 1,931.95 = 621.29 : x
  2. Step 2: Convert to fraction form
    1,288.73/1,931.95 = 621.29/x
  3. Step 3: Cross multiply
    1,288.73x = 1,931.95 × 621.29
  4. Step 4: Simplify right side
    1,288.73x = 1,200,301.22
  5. Step 5: Solve for x
    x = 1,200,301.22/1,288.73
  6. Step 6: Final answer
    x = 931.38

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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.