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Finding the Fourth Proportional to 30.80, 42.22 and 30.35

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Solution

The fourth proportional to 30.80, 42.22 and 30.35 is: 41.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.80 : 42.22 = 30.35 : x
  2. Step 2: Convert to fraction form
    30.80/42.22 = 30.35/x
  3. Step 3: Cross multiply
    30.80x = 42.22 × 30.35
  4. Step 4: Simplify right side
    30.80x = 1,281.38
  5. Step 5: Solve for x
    x = 1,281.38/30.80
  6. Step 6: Final answer
    x = 41.60

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.