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Finding the Fourth Proportional to 934.40, 1,288.14 and 639.20

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Solution

The fourth proportional to 934.40, 1,288.14 and 639.20 is: 881.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    934.40 : 1,288.14 = 639.20 : x
  2. Step 2: Convert to fraction form
    934.40/1,288.14 = 639.20/x
  3. Step 3: Cross multiply
    934.40x = 1,288.14 × 639.20
  4. Step 4: Simplify right side
    934.40x = 823,379.09
  5. Step 5: Solve for x
    x = 823,379.09/934.40
  6. Step 6: Final answer
    x = 881.18

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.