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Finding the Fourth Proportional to 30.68, 42.24 and 28.61

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Solution

The fourth proportional to 30.68, 42.24 and 28.61 is: 39.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.68 : 42.24 = 28.61 : x
  2. Step 2: Convert to fraction form
    30.68/42.24 = 28.61/x
  3. Step 3: Cross multiply
    30.68x = 42.24 × 28.61
  4. Step 4: Simplify right side
    30.68x = 1,208.31
  5. Step 5: Solve for x
    x = 1,208.31/30.68
  6. Step 6: Final answer
    x = 39.39

Related Problems

Find fourth proportional to 15.34, 21.12 and 14.30
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1.5x scale

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.