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Finding the Fourth Proportional to 386.40, 577.41 and 278.40

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Solution

The fourth proportional to 386.40, 577.41 and 278.40 is: 416.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.40 : 577.41 = 278.40 : x
  2. Step 2: Convert to fraction form
    386.40/577.41 = 278.40/x
  3. Step 3: Cross multiply
    386.40x = 577.41 × 278.40
  4. Step 4: Simplify right side
    386.40x = 160,750.94
  5. Step 5: Solve for x
    x = 160,750.94/386.40
  6. Step 6: Final answer
    x = 416.02

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.