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Finding the Fourth Proportional to 280.03, 386.78 and 210.40

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Solution

The fourth proportional to 280.03, 386.78 and 210.40 is: 290.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.03 : 386.78 = 210.40 : x
  2. Step 2: Convert to fraction form
    280.03/386.78 = 210.40/x
  3. Step 3: Cross multiply
    280.03x = 386.78 × 210.40
  4. Step 4: Simplify right side
    280.03x = 81,378.51
  5. Step 5: Solve for x
    x = 81,378.51/280.03
  6. Step 6: Final answer
    x = 290.61

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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.