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Finding the Fourth Proportional to 277.80, 416.65 and 85.38

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Solution

The fourth proportional to 277.80, 416.65 and 85.38 is: 128.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    277.80 : 416.65 = 85.38 : x
  2. Step 2: Convert to fraction form
    277.80/416.65 = 85.38/x
  3. Step 3: Cross multiply
    277.80x = 416.65 × 85.38
  4. Step 4: Simplify right side
    277.80x = 35,573.58
  5. Step 5: Solve for x
    x = 35,573.58/277.80
  6. Step 6: Final answer
    x = 128.05

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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.