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Finding the Fourth Proportional to 980.21, 1,470.13 and 286.72

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Solution

The fourth proportional to 980.21, 1,470.13 and 286.72 is: 430.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.21 : 1,470.13 = 286.72 : x
  2. Step 2: Convert to fraction form
    980.21/1,470.13 = 286.72/x
  3. Step 3: Cross multiply
    980.21x = 1,470.13 × 286.72
  4. Step 4: Simplify right side
    980.21x = 421,515.67
  5. Step 5: Solve for x
    x = 421,515.67/980.21
  6. Step 6: Final answer
    x = 430.03

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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.