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Finding the Fourth Proportional to 388.71, 535.45 and 290.30

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Solution

The fourth proportional to 388.71, 535.45 and 290.30 is: 399.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.71 : 535.45 = 290.30 : x
  2. Step 2: Convert to fraction form
    388.71/535.45 = 290.30/x
  3. Step 3: Cross multiply
    388.71x = 535.45 × 290.30
  4. Step 4: Simplify right side
    388.71x = 155,441.14
  5. Step 5: Solve for x
    x = 155,441.14/388.71
  6. Step 6: Final answer
    x = 399.89

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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.