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Finding the Fourth Proportional to 30.90, 42.67 and 25.53

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Solution

The fourth proportional to 30.90, 42.67 and 25.53 is: 35.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.90 : 42.67 = 25.53 : x
  2. Step 2: Convert to fraction form
    30.90/42.67 = 25.53/x
  3. Step 3: Cross multiply
    30.90x = 42.67 × 25.53
  4. Step 4: Simplify right side
    30.90x = 1,089.37
  5. Step 5: Solve for x
    x = 1,089.37/30.90
  6. Step 6: Final answer
    x = 35.25

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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.