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Finding the Fourth Proportional to 388.36, 535.69 and 305.74

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Solution

The fourth proportional to 388.36, 535.69 and 305.74 is: 421.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.36 : 535.69 = 305.74 : x
  2. Step 2: Convert to fraction form
    388.36/535.69 = 305.74/x
  3. Step 3: Cross multiply
    388.36x = 535.69 × 305.74
  4. Step 4: Simplify right side
    388.36x = 163,777.65
  5. Step 5: Solve for x
    x = 163,777.65/388.36
  6. Step 6: Final answer
    x = 421.72

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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.