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Finding the Fourth Proportional to 280.71, 420.78 and 189.18

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Solution

The fourth proportional to 280.71, 420.78 and 189.18 is: 283.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.71 : 420.78 = 189.18 : x
  2. Step 2: Convert to fraction form
    280.71/420.78 = 189.18/x
  3. Step 3: Cross multiply
    280.71x = 420.78 × 189.18
  4. Step 4: Simplify right side
    280.71x = 79,603.16
  5. Step 5: Solve for x
    x = 79,603.16/280.71
  6. Step 6: Final answer
    x = 283.58

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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.