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Finding the Fourth Proportional to 810.70, 1,120.05 and 770.74

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Solution

The fourth proportional to 810.70, 1,120.05 and 770.74 is: 1,064.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.70 : 1,120.05 = 770.74 : x
  2. Step 2: Convert to fraction form
    810.70/1,120.05 = 770.74/x
  3. Step 3: Cross multiply
    810.70x = 1,120.05 × 770.74
  4. Step 4: Simplify right side
    810.70x = 863,267.34
  5. Step 5: Solve for x
    x = 863,267.34/810.70
  6. Step 6: Final answer
    x = 1,064.84

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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.