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Finding the Fourth Proportional to 145.80, 218.38 and 84.78

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Solution

The fourth proportional to 145.80, 218.38 and 84.78 is: 126.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.80 : 218.38 = 84.78 : x
  2. Step 2: Convert to fraction form
    145.80/218.38 = 84.78/x
  3. Step 3: Cross multiply
    145.80x = 218.38 × 84.78
  4. Step 4: Simplify right side
    145.80x = 18,514.26
  5. Step 5: Solve for x
    x = 18,514.26/145.80
  6. Step 6: Final answer
    x = 126.98

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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.