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Finding the Fourth Proportional to 38.40, 52.80 and 31.84

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Solution

The fourth proportional to 38.40, 52.80 and 31.84 is: 43.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.40 : 52.80 = 31.84 : x
  2. Step 2: Convert to fraction form
    38.40/52.80 = 31.84/x
  3. Step 3: Cross multiply
    38.40x = 52.80 × 31.84
  4. Step 4: Simplify right side
    38.40x = 1,681.15
  5. Step 5: Solve for x
    x = 1,681.15/38.40
  6. Step 6: Final answer
    x = 43.78

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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.