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Finding the Fourth Proportional to 388.81, 536.87 and 311.53

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Solution

The fourth proportional to 388.81, 536.87 and 311.53 is: 430.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.81 : 536.87 = 311.53 : x
  2. Step 2: Convert to fraction form
    388.81/536.87 = 311.53/x
  3. Step 3: Cross multiply
    388.81x = 536.87 × 311.53
  4. Step 4: Simplify right side
    388.81x = 167,251.11
  5. Step 5: Solve for x
    x = 167,251.11/388.81
  6. Step 6: Final answer
    x = 430.16

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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.