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Finding the Fourth Proportional to 388.64, 536.80 and 318.88

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Solution

The fourth proportional to 388.64, 536.80 and 318.88 is: 440.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.64 : 536.80 = 318.88 : x
  2. Step 2: Convert to fraction form
    388.64/536.80 = 318.88/x
  3. Step 3: Cross multiply
    388.64x = 536.80 × 318.88
  4. Step 4: Simplify right side
    388.64x = 171,174.78
  5. Step 5: Solve for x
    x = 171,174.78/388.64
  6. Step 6: Final answer
    x = 440.45

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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.