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Finding the Fourth Proportional to 1,428.71, 2,143.07 and 388.72

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Solution

The fourth proportional to 1,428.71, 2,143.07 and 388.72 is: 583.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,428.71 : 2,143.07 = 388.72 : x
  2. Step 2: Convert to fraction form
    1,428.71/2,143.07 = 388.72/x
  3. Step 3: Cross multiply
    1,428.71x = 2,143.07 × 388.72
  4. Step 4: Simplify right side
    1,428.71x = 833,054.17
  5. Step 5: Solve for x
    x = 833,054.17/1,428.71
  6. Step 6: Final answer
    x = 583.08

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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.