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Finding the Fourth Proportional to 208.71, 312.80 and 99.03

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Solution

The fourth proportional to 208.71, 312.80 and 99.03 is: 148.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.71 : 312.80 = 99.03 : x
  2. Step 2: Convert to fraction form
    208.71/312.80 = 99.03/x
  3. Step 3: Cross multiply
    208.71x = 312.80 × 99.03
  4. Step 4: Simplify right side
    208.71x = 30,975.27
  5. Step 5: Solve for x
    x = 30,975.27/208.71
  6. Step 6: Final answer
    x = 148.41

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.