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Finding the Fourth Proportional to 117.80, 162.40 and 100.28

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Solution

The fourth proportional to 117.80, 162.40 and 100.28 is: 138.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    117.80 : 162.40 = 100.28 : x
  2. Step 2: Convert to fraction form
    117.80/162.40 = 100.28/x
  3. Step 3: Cross multiply
    117.80x = 162.40 × 100.28
  4. Step 4: Simplify right side
    117.80x = 16,285.47
  5. Step 5: Solve for x
    x = 16,285.47/117.80
  6. Step 6: Final answer
    x = 138.25

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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.