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Finding the Fourth Proportional to 805.21, 1,106.71 and 711.40

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Solution

The fourth proportional to 805.21, 1,106.71 and 711.40 is: 977.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.21 : 1,106.71 = 711.40 : x
  2. Step 2: Convert to fraction form
    805.21/1,106.71 = 711.40/x
  3. Step 3: Cross multiply
    805.21x = 1,106.71 × 711.40
  4. Step 4: Simplify right side
    805.21x = 787,313.49
  5. Step 5: Solve for x
    x = 787,313.49/805.21
  6. Step 6: Final answer
    x = 977.77

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.