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Finding the Fourth Proportional to 388.95, 583.49 and 128.95

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Solution

The fourth proportional to 388.95, 583.49 and 128.95 is: 193.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.95 : 583.49 = 128.95 : x
  2. Step 2: Convert to fraction form
    388.95/583.49 = 128.95/x
  3. Step 3: Cross multiply
    388.95x = 583.49 × 128.95
  4. Step 4: Simplify right side
    388.95x = 75,243.82
  5. Step 5: Solve for x
    x = 75,243.82/388.95
  6. Step 6: Final answer
    x = 193.45

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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.