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Finding the Fourth Proportional to 100.51, 150.50 and 78.80

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Solution

The fourth proportional to 100.51, 150.50 and 78.80 is: 117.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.51 : 150.50 = 78.80 : x
  2. Step 2: Convert to fraction form
    100.51/150.50 = 78.80/x
  3. Step 3: Cross multiply
    100.51x = 150.50 × 78.80
  4. Step 4: Simplify right side
    100.51x = 11,858.84
  5. Step 5: Solve for x
    x = 11,858.84/100.51
  6. Step 6: Final answer
    x = 117.99

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.