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Finding the Fourth Proportional to 388.91, 536.82 and 305.66

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Solution

The fourth proportional to 388.91, 536.82 and 305.66 is: 421.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.91 : 536.82 = 305.66 : x
  2. Step 2: Convert to fraction form
    388.91/536.82 = 305.66/x
  3. Step 3: Cross multiply
    388.91x = 536.82 × 305.66
  4. Step 4: Simplify right side
    388.91x = 164,084.40
  5. Step 5: Solve for x
    x = 164,084.40/388.91
  6. Step 6: Final answer
    x = 421.91

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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.