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Finding the Fourth Proportional to 1,284.30, 1,771.74 and 812.79

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Solution

The fourth proportional to 1,284.30, 1,771.74 and 812.79 is: 1,121.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,284.30 : 1,771.74 = 812.79 : x
  2. Step 2: Convert to fraction form
    1,284.30/1,771.74 = 812.79/x
  3. Step 3: Cross multiply
    1,284.30x = 1,771.74 × 812.79
  4. Step 4: Simplify right side
    1,284.30x = 1,440,052.55
  5. Step 5: Solve for x
    x = 1,440,052.55/1,284.30
  6. Step 6: Final answer
    x = 1,121.27

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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.